Solve this issue

All your checkboxes inside #survey-form should have a value attribute and value

what does this mean ,i have given value attribute but it does not work?
Here is my code

/***
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Registration Form</title>
    <link rel="stylesheet" href="styles.css" />
  </head>
  <body>
      <h1 id="title">freeCodeCamp Survey Form<h1>
      <p id="description">Thank you for taking the time to help us improve the platform<p>
        <form id="survey-form">
  <fieldset>
    <label for="name" id="name-label">Name: <input id="name" name="name" type="text"  required placeholder="adffgggvh"/><br></label>
    <label for="email" id="email-label">Email: <input id="email" name="email" placeholder="ashok@gmail.com" type="email" required /><br></label>
    <label for="age" id="number-label">Age(optional): <input id="number" name="age" type="number" min="12" max="45" required  placeholder="23"/></label>
</fieldset>
<fieldset>
    <label for="referrer">Which option best describes your current role?
          <select id="dropdown" name="referrer">
            <option value="">Select current role</option>
            <option value="1">Student</option>
            <option value="2">Full Time Job</option>
            <option value="3">Full Time Learner</option>
            <option value="3">Prefer Not to say</option>
            <option value="4">Others</option>
          </select>
        </label>
  <p>Would you recommend freeCodeCamp to a friend?</p>
  <label for="definetly"><input id="definetly" type="radio"  name="group1" class="inline" value="definetly" /> Definitely</label>
<label for="maybe"><input id="maybe" type="radio" name="group1" class="inline" value="maybe" /> May be</label>
<label for="Not Sure"><input id="Not sure" type="radio" name="group1" class="inline" value="Notsure" /> Not Sure</label>
<p>What would you like to see improved? (Check all that apply)</p>
<label for="Front end project" name="Front-end Projects">
          <input value="0" id="Front-end Projects" type="checkbox" required  class="inline" /> Front-end Projects
       <br> </label>
<label for="Back end project" name="Back-end Projects">
          <input id="Back-end Projects" type="checkbox" required  class="inline" value="1" /> Back-end Projects
        <br></label>
<label for="Data Visualization" name="Data Visualization">
          <input id="Data Visualization" type="checkbox" required  class="inline" value="2"/>Data Visualization<br>
        </label>
<label for="Challenges" name="Challenges">
          <input id="Challenges" type="checkbox" required  class="inline"  value=""3/> Challenges<br>
        </label>
<label for="Open Source Community" name="Open Source Community">
          <input id="Open Source Community" type="checkbox" required  class="inline" value="4"/> Open Source Community<br>
        </label>
<label for="Back end project" name="Back-end Projects">
          <input id="Back-end Projects" type="checkbox" required  class="inline"  value="5"/> Back-end Projects<br>
        </label>
<label for="Gitter help rooms" name="Gitter help rooms">
          <input id="Gitter help rooms" type="checkbox" required  class="inline" value="6"/> Gitter help rooms<br>
        </label>
<label for="Videos" name="Videos">
          <input id="Videos" type="checkbox" required  class="inline"  value="7"/> Videos<br>
        </label>
<label for="City Meetups" name="City Meetups">
          <input id="City Meetups" type="checkbox" required  class="inline" value="8"/>City Meetups<br>
        </label>
<label for="Wiki" name="Wiki">
          <input id="Wiki" type="checkbox" required  class="inline"  value="9"/> Wiki<br>
        </label>
<label for="Forum" name="Forum">
          <input id="Forum" type="checkbox" required  class="inline"  value="10"/>Forum<br>
        </label>
<label for="Additional Courses" name="Additional Courses">
          <input id="Additional Courses" type="checkbox" required  class="inline" value="11"/> Additional Courses</label>
<p>Any comments or suggestions?<textarea id="bio" name="bio" rows="3" cols="30" placeholder="I like coding on the beach..."></textarea><p>
<input type="submit" value="Submit" id="submit"/>
  </fieldset>
  </form>
  </body>
***/
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Registration Form</title>
    <link rel="stylesheet" href="styles.css" />
  </head>
  <body>
      <h1 id="title">freeCodeCamp Survey Form<h1>
      <p id="description">Thank you for taking the time to help us improve the platform<p>
        <form id="survey-form">
  <fieldset>
    <label for="name" id="name-label">Name: <input id="name" name="name" type="text"  required placeholder="adffgggvh"/><br></label>
    <label for="email" id="email-label">Email: <input id="email" name="email" placeholder="ashok@gmail.com" type="email" required /><br></label>
    <label for="age" id="number-label">Age(optional): <input id="number" name="age" type="number" min="12" max="45" required  placeholder="23"/></label>
</fieldset>
<fieldset>
    <label for="referrer">Which option best describes your current role?
          <select id="dropdown" name="referrer">
            <option value="">Select current role</option>
            <option value="1">Student</option>
            <option value="2">Full Time Job</option>
            <option value="3">Full Time Learner</option>
            <option value="3">Prefer Not to say</option>
            <option value="4">Others</option>
          </select>
        </label>
  <p>Would you recommend freeCodeCamp to a friend?</p>
  <label for="definetly"><input id="definetly" type="radio"  name="group1" class="inline" value="definetly" /> Definitely</label>
<label for="maybe"><input id="maybe" type="radio" name="group1" class="inline" value="maybe" /> May be</label>
<label for="Not Sure"><input id="Not sure" type="radio" name="group1" class="inline" value="Notsure" /> Not Sure</label>
<p>What would you like to see improved? (Check all that apply)</p>
<label for="Front end project" name="Front-end Projects">
          <input value="0" id="Front-end Projects" type="checkbox" required  class="inline" /> Front-end Projects
       <br> </label>
<label for="Back end project" name="Back-end Projects">
          <input id="Back-end Projects" type="checkbox" required  class="inline" value="1" /> Back-end Projects
        <br></label>
<label for="Data Visualization" name="Data Visualization">
          <input id="Data Visualization" type="checkbox" required  class="inline" value="2"/>Data Visualization<br>
        </label>
<label for="Challenges" name="Challenges">
          <input id="Challenges" type="checkbox" required  class="inline"  value=""3/> Challenges<br>
        </label>
<label for="Open Source Community" name="Open Source Community">
          <input id="Open Source Community" type="checkbox" required  class="inline" value="4"/> Open Source Community<br>
        </label>
<label for="Back end project" name="Back-end Projects">
          <input id="Back-end Projects" type="checkbox" required  class="inline"  value="5"/> Back-end Projects<br>
        </label>
<label for="Gitter help rooms" name="Gitter help rooms">
          <input id="Gitter help rooms" type="checkbox" required  class="inline" value="6"/> Gitter help rooms<br>
        </label>
<label for="Videos" name="Videos">
          <input id="Videos" type="checkbox" required  class="inline"  value="7"/> Videos<br>
        </label>
<label for="City Meetups" name="City Meetups">
          <input id="City Meetups" type="checkbox" required  class="inline" value="8"/>City Meetups<br>
        </label>
<label for="Wiki" name="Wiki">
          <input id="Wiki" type="checkbox" required  class="inline"  value="9"/> Wiki<br>
        </label>
<label for="Forum" name="Forum">
          <input id="Forum" type="checkbox" required  class="inline"  value="10"/>Forum<br>
        </label>
<label for="Additional Courses" name="Additional Courses">
          <input id="Additional Courses" type="checkbox" required  class="inline" value="11"/> Additional Courses</label>
<p>Any comments or suggestions?<textarea id="bio" name="bio" rows="3" cols="30" placeholder="I like coding on the beach..."></textarea><p>
<input type="submit" value="Submit" id="submit"/>
  </fieldset>
  </form>
  </body>

I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (').

This looks wrong? (Maybe this is the issue)

Also pls post a link to the question if you still need help.

Already got it.
Anyway Thanks