There are two different ways to change your name.

• While you are in a team, you can tap on the “Settings” button at the upper right corner of the home screen and tap on the “Change Name” button to change your name. 
• At the upper left corner of the home screen, click on the "Profile" button, and then tap on your "Avatar." After that, you will see the "Edit Profile" menu, where you can change your name.

Don’t forget that you can change your name only once.