How to create an "add friends" feature for my app?

There’s some really good information on ‘following’ users here, which you might be able to adapt: How to Allow Users to Follow Others - Adalo Resources

Would your ‘friends’ would have the same relationships as followers? @pford has done some great videos on making the follows work too - Creating the Follow Function in Adalo (Followers and Following Others) - #2 by eliorb