create custom php page in angular script

I have a php script which I believe is built with bootstrap or laravel and angular frameworks. I want to just add an custom php page inside the script simple as "Hello world".

here is the script https://codecanyon.net/item/bemusic-music-streaming-engine/13616699

script does give offer to add custom page via admin, but those are simple html

im sure someone here may be able to help you, but have your tried freelancer? you can get someone to do this there for like $25. i always use their platform for cheap work.

If someone can guide me, I could do it myself. Just not advance coder. I tried look for html or php codes in those files. Could find where to edit. I think the code is compiled? I do have source code, maybe need to work on that and compile again? I’m not sure

thanks