Credit Card Template

Yep, that's exactly what the Credit Card Template is for. It lets you take the information entered in your Access database and send a one-time transaction to PayPal's Payflow Gateway Pro, so the user doesn't have to enter everything twice.

It is designed around PayPal's gateway, not Venmo. Venmo is owned by PayPal, but I don't know whether its current API supports this particular type of direct payment processing. You would need to check Venmo's developer documentation for that.

Also, for something like event registration, I would strongly recommend not storing card numbers in Access. A better approach is usually to send the user to a hosted payment page or use a payment processor's checkout system, then save only the payment confirmation or transaction ID in your database. That keeps the sensitive card information out of your database entirely.

If you want to store credit card information for recurring billing, for example, definitely use SQL Server with proper security.