Plugin creation - Can I copy .cpp and/or .h files from Epic's plugins?

Hi everyone. This might be noob question but please bear with me.

I’m currently creating a plugin, but it uses a plugin that Epic created “OnlineSubsystemFacebook”.

So, my question is, can I copy and modify those files or module to my plugin directory to be used by my plugin?
or do I have to extend that plugin? if so, how do I go about doing that?

Thanks

You definitely can modify it if it’s for the game, not sure if spretly as plugin. I will move this question to Legal category, somebody for Epic legal team might answer this way

Bump. Please help

Thank you for that, ! I hope they do answer.

Bump again. Anyone?

Hello? Can anyone help?

Was this ever figured out?