The language of the game depends on the system language of your device. If the device you play on is in English, then the game will be displayed in English, too.
So to change the language of the game you need to change the language in the Settings of your device.
The game is currently available in English, Spanish, German, French, Italian, Portuguese, Polish, Dutch, Russian, Japanese, Korean, Chinese (Simplified) and Chinese (Traditional). If the language of your device is not among the mentioned ones, you can change it in the settings of your device to one of the stated languages and the game will run in this language.
So to change the language of the game you need to change the language in the Settings of your device.
The game is currently available in English, Spanish, German, French, Italian, Portuguese, Polish, Dutch, Russian, Japanese, Korean, Chinese (Simplified) and Chinese (Traditional). If the language of your device is not among the mentioned ones, you can change it in the settings of your device to one of the stated languages and the game will run in this language.