Thanks for reaching out to us here, @contact152.
I have some information about applying a credit memo through mobile app. While some features may not be able to view in the app, you'll want to open QuickBooks account using a browser. From there, apply or record the credit.
Here's the list of supported browsers: System requirements for QuickBooks Online, Accountant, Payroll, and QuickBooks Self-Employed.
Once you're able to log in, try creating and applying the credit notes again. Refer to this guide for more information: Create and apply credit notes or delayed credits in QuickBooks Online.
With the above recommendation, you're able to apply the credit note through your mobile phone.
In case you need help managing customer-related tasks, feel free to browse this link to go to the page: Sales and Customers.
Please let us know if you have other questions or concerns with credit notes. I'm more than happy to assist you. Take care and have a good one.
