Depending on what your Facebook is about, you could check out Patreon and see if you can link whatever it is you do on Facebook to their program.
In a nutshell, you let everyone know what your Facebook is about, and people can become Patrons, by sending you money every month. You can give them options to pay more monthly and those that choose to do so get a few extra's.
You can always put up a one dollar plan, saying "Thanks for your support" with no additional benefits. Some people do this to say "I like what you got, and I like to see you keep it up."
