Niantic has announced that Turkish language support has been added to Pokémon GO.

Turkish language support for Pokémon GO!

Trainers,
We’re happy to announce we’ve added Turkish language support for Pokémon GO!

You can now set your in-game language to Turkish. Whether you’re just starting your adventure or you’re a seasoned Trainer with years of experience, we’re elated to embark on this journey with you as we work to make Pokémon GO available to even more people. We aim to continually improve and update the Turkish-language version of Pokémon GO.

Details on upcoming events will also be published in Turkish on the blog, on Twitter @PokemonGOAppTR, and on Facebook at PokemonGOAppTR.

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

Source: https://pokemongolive.com/en/post/turkish-language-support/