JavaScript web game project. Can it be load on phaser 3

Good morning to you all, please I am having a big challenging question which I need to clear my doubt.
I am a JavaScript game developer, I build JavaScript game for web browser. The question is, "phaser 3 game engine is a JavaScript framework, is it possible for me to load my ready-made/already developed game with JavaScript on the Phaser 3 game engine to to work on additional functionalities or modify my game?

I’ll appreciate responses from you expert and experienced Phaser 3 game developer’s.
Thanks,
DCent