i cannot get the donate button to appear on my groups fb page

[rosettacozart]

just set up my paypal for our nonprofit  trying to add  "donate " button   unable to get it to show up on the fb page     i have a link in my posts but i have to add it everytime i post      do i need a website to add a donate button   i cannot figure out where to paste the copied code  and html doesnt show up   thanks