why wont my js code work? it works on solelearn but not on vs code or notepad.

Question

I am using a code I got from someone and decided to tweak it a bit and then I went to link the files together on VS code/notepad but it's not working, I replaced all the comment symbols as they didn't seem to comment properly, but still not working.
if possible can someone please fix it for me or tell me what to do, also how I would link these files.
ps, I don't know javascript very well just started to learn it so it may be obvious things.

Answer 1

For many codes will be needed a server then they will work.

Answer 2

martin taylor, i did

Answer 3

https://code.sololearn.com/WehCc307rV6C/?ref=app
this is the code