To upload your profile picture and edit your about information on the app you need to claim your verified artist account first. If you are yet to do so, please see the link below for a quick guide on how to do this :).
How to Claim/Access your Verified Artiste Profile
After your claim request is approved, kindly follow the steps below to edit these details.
1. Click on the Account tab, then click on I'm an Artist
2. Click on Profile
3. Edit the details as you desire, all done.