Hi there, @alexandra1367.
To change your email address for your QuickBooks email receipts, it must be verified through Multi-factor authentication. You'll also need to make sure that your email address is associated with your QuickBooks Self-Employed account.
Here are the access points in your QBSE App:
You can review this article to know the next steps upon changing your email for receipts forwarding in QBSE.
Count me in if you need anything else. I'll be here to help. Keep safe.