Is it possible to work Strapi using PhP?

I’m reltively new to Strapi but from what I can tell its a standalone webserver that exposes API endpoints which would mean the answer to your question is yes.

You would interact with your strapi server like any other rest API via PHP. There’s plenty of online resources so I wont post anything exhaustive but here’s a small example: http - How do I send a POST request with PHP? - Stack Overflow