Where is the :blue ; join this group button ?

Question

Where is the :blue ; join this group button ?

Answer 1

if you're already a member, you wont see it. none members see it on the right top of page-

if it's a closed group, there wont be a blue join this group tab

Answer 2

It is generally on the upper right-hand side of the page but if you are the member of the group you won't be able to see it.