Avatars are in-game profile pictures that you unlock by fulfilling certain conditions.

To change your avatar:  

• Go to the home page of the game.
• Select the picture on the top-left of the page.  
• Once your Profile opens, select the pen button on the lower left of the screen.  
• Choose the new avatar you want to use.  

You can only use avatars that you have already unlocked.  

Greyed out avatars on your avatar list need to be unlocked. You can check the unlock condition for each avatar at the bottom of the screen.