Basic JavaScript - Understanding Undefined Value returned from a Function

Tell us what’s happening:
Describe your issue in detail here.
Ive followed all the instructions so far but it still shows errors, so i need assistance please

   **Your code so far**
// Setup
let sum = 0;

function addThree() {
 sum = sum + 3;
}

// Only change code below this line
function Addfive() {
let sum = sum + 5;
}


// Only change code above this line

addThree();
addFive();
   **Your browser information:**

User Agent is: Mozilla/5.0 (X11; CrOS x86_64 14588.123.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.0.0 Safari/537.36

Challenge: Basic JavaScript - Understanding Undefined Value returned from a Function

Link to the challenge:

@camperbot Could u help me

nvm i got the issue ps : i cant delete my own post