Step 1. Click the avatar icon in the bottom right corner to move to your profile
Step 2. Now select and click ‘Edit Profile’ below your bio
Step 3. Then click the username field and here type in the new handle that you have thought of
Step 4. Press ‘done’
Step 5. In case you want to change your display name after this then type in the name field instead of that.
For More Details To Update names, email, profile, etc Click Below