Thanks for using QuickBooks to keep tracking your business transactions, @waremark. I know how important it is to retain access to your data. Let me help you with that.

Since you are no longer utilizing your QuickBooks Desktop Pro 2020. You can export your data from the Desktop version to QuickBooks Online to maintain access to your data. 

Before you get started, rename your file on the old computer to avoid using the incorrect file. To do this, create a backup and restore your file by performing the steps below: 

1. Create a backup of your file on your computer.
2. Copy the backup file to your QuickBooks Desktop (QBDT) using, either a flash drive or through a network if the computers are connected.
3. Follow the steps to restore the backup on your new computer. Remember, it should have a unique file name. 

Once done, you can now view and export your reports. Follow the steps below. 

For more details, see Solution 1 through this article: Move Your Company Files To Another Computer. 

To ensure that you'll get to secure your data, you can follow Fiat Lux - ASIA's suggestion to use a third-party app that can help convert your converted data with a third-party tool or purchase a third-party conversion service. Also, you can use the data export tool. It helps download your company data onto your computer for safekeeping. 

Additionally, I've attached here an article, that will discuss details about what to expect when converting files from QBDT to QBO: Switch from QuickBooks Desktop to QuickBooks Online. You will know what data doesn't convert when you migrate from QBDT to QBO.

Moreover, you can check out this article: QuickBooks Desktop is being discontinued. It will also help you move your data to QuickBooks Online or download your data to move out of QBDT. 

I'll address any other issues you may have about the supportability of QuickBooks Desktop versions. If you'd want me to handle your transactions and lists, you can comment below, and I'll assist you. You've got a good one.