The official Twitter account for Pokémon GO has announced that Trainer Battles has gone live for all players level 20 and up.
#GOBattle ALERT: Trainers level 20 and up can now start their first Trainer Battles! Stay tuned, as we look forward to rolling out this feature to even more Trainers soon.
— Pokémon GO is ready to #GOBattle (@PokemonGoApp) December 13, 2018
We’ll update with more news and details shortly.
Source: Daily.pokecommunity