Hi there, @SAO1.

It isn't advisable to update your desktop to Sequoia if you are using QuickBooks for Mac 2020 version because the said version doesn't support it.

Currently, These are the only supported QB for Mac versions for Sequoia OS as of now:

• QuickBooks Mac 2024 R5.1
• QuickBooks Mac 2023 R7.2
• QuickBooks Mac 2022 R12

However, you can use a previous later version of Sequoia so that your QB Mac will work properly.

On the other hand, you can visit this article to update your QB for Mac to the latest release: Update QuickBooks for Mac to the latest release.

Additionally, you can visit this article for future reference to learn how to import your data into QuickBooks for Mac: Import data into QuickBooks for Mac.
 

You can always return to this thread for further assistance.