Change Text of HTML object through JavaScript in PHP

Question

I need help to resolve this problem:

https://code.sololearn.com/wkoyVR67fePK/#php

Answer 1

parsing html forms to php and receiving it with $_get...$_post doesn't work on Sololearn

Answer 2

I tried this on my desktop IDE i.e. PHPStorm. It doesn't work there too. :-(