When I do an invoice I have to do it from my laptop online cause it automatically generates my next invoice number, but it doesn’t in the app.

Hi there, @stpaulsclc.

Let's clear QuickBooks Online App data to isolate this issue. Let me guide you how.

For Android: 

1. Go to the Options menu.
2. Click Settings.
3. Select Refresh Data.
4. Then choose Yes.

For IOS:

1. Click Menu.
2. Select Help & Feedback.
3. Click Refresh Data.
4. Then select Refresh.

Here's an article you can check for more details and troubleshooting steps: Troubleshooting Quick-Start Guide for the QuickBooks Online app.

I'm also adding this article that can guide you through the detailed steps in entering a delayed credit to your customer: Enter and apply credit notes and delayed credits in QuickBooks Online.

 
Do get back to us anytime you have other concerns or questions. I'm always around to help. Take care and stay healthy.