Good day, veeda. I hope you're doing well today.
I have some insight into your concern with copying the file to the other version of QuickBooks Online.
QuickBooks Online Advanced features data backup. If you wish to copy the file to QuickBooks Online Plus, you can look for a third-party application that lets you do the tasks.
For guidance on what app to use, go to the Apps menu in your QBO account and browse for one that suits your business needs.

I'm also adding an article to restore your QuickBooks Online Advanced company for guidance.
Know that you're always welcome to post again anytime if you need help again in the future. The Community is here to back you up.