How to import a Live stream link to processing?

Well, sure, if you think it is easy, maybe it is–try it!

Do you want your sketch to send video TO facebook, or get video FROM Facebook? Very different. TO facebook is well-understood–they have an API. But I thought you wanted to load streams from facebook and process them in your sketch. Maybe I don’t understand what your sketch is supposed to do–you could explain more.

You might also consider looking at work by p5.js users who work with streaming video–for example, I believe that @lmccart does.

See also related discussions of point-to-point streams (non-platform), like