The language of the application's interface will be the same as the one you have set on your device. To change it, you will have to do it directly from your device's menu, in the language settings section.
On the other hand, remember that you will be able to select the language of a classic game before it starts. To do this, once you select Classic Mode, you will need to press the tool icon on the top right-hand corner of your screen.
Keep in mind that the language will always be determined by the user who created the game. For this reason, you may receive invitations to play in languages you don't normally play in; if you prefer, you can decline the game and continue in your preferred language.
We invite you to visit the article: How can I reject a game?