https://www.techradar.com/news/pokemon-go-will-soon-get-trading-and-friends-lists

After two years of inviting players to catch ‘em all, Pokemon Go will soon offer the ability to trade ‘em too. Announced by Niantic, new trading and friends list features will be coming to the game over the next few weeks.

The first of the two features to roll out will be the friends list, which is expected to be available within a matter of days. Adding another trainer to your friend list will be as simple as swapping a trainer code with someone, sending them a friend request and waiting for them to accept or reject it.