This is a great question and I'll gladly walk you through the steps of sorting out your situation here.
Once you set up a recurring transaction in QuickBooks Online, there are certain details you can change, such as the person the transaction applies to, the name of the transaction template, the frequency, and so on. Changing the type of transaction, however, isn't one of the options.
Don't worry! All you'll need to do is delete the current recurring transaction template and create a new one with the parameters you'd like. Follow these steps.
Select the Gear icon in the upper right of your account.
Choose Recurring Transactions.
Find the currently set up transaction template and click the drop-down arrow in the Action column.
Select Delete.
Click Yes to confirm.
Once you've done that, you can create the recurring transaction for the cheque from the same screen. Here's how.