Don't know

If you ask how to play with your friend, the best way is to send him a referal link (top left, just under your avatar), then he need to follow that link and get the game. He must not have Raid already installed, as you will not get the gifts from referal link. Then in game, invite him in your clan. That's the closest interactuon you may have with him in game. 

If you ask how to make friends in general, well that's another thing. You better take a look around yourself, don't search them in some games. :) 

Daering said:

If you ask how to play with your friend, the best way is to send him a referal link (top left, just under your avatar), then he need to follow that link and get the game. He must not have Raid already installed, as you will not get the gifts from referal link.

And you and your friend must NOT respect privacy (agree to targeted ads in android system, do not reset google ads ID ..., allow everything client asks for - even if you know it is just for spying purposes ...)

If you fail privacy check game will run on friends device - it will just not be linked to you in terms of rewards obtained after he reaches lvls required)