Hi there, @Savvy4.
In QuickBooks Online (QBO), matching two downloaded transactions to one recorded tax payment isn't an option. In the meantime, if it's a manually paid transaction, you can delete the one tax payment created in QBO and recreate it again into two individual transactions. Once done, you can now match the two amounts on the downloaded payment.
However, if the tax payment is processed electronically, you can exclude the downloaded bank transaction, then clear the tax payment into the register.
For more information about managing your transactions, see this article for a guide: Categorize and match online bank transactions in QuickBooks Online.
After that, you can reconcile the account to compare the list of transactions from your bank statements with what you recorded in QuickBooks.
Let me know if there's anything else I can help matching your transaction. I'm always around to help.