You'll have to cancel your QuickBooks Online Payments subscription to remove the payment option. Let me help you how to do it.
To cancel, you need to contact Payment Support. One of our phone agents will assist you with the cancellation.
After that, you'll want to edit your invoice template to remove the option. Here are the steps:
I've also added this link for your reference in the future: https://quickbooks.intuit.com/community/Payments/bd-p/payments-articles?label=QuickBooks%20Online.
Get back to me if there's anything else you need. I'm just a comment away.