The input element that you see in the code should be nested inside your form element. Right now, you have your input element outside of your form element and your form element has nothing inside. Try fixing it and your code should work fine afterwards.
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.