Credit Card Auth.Net is required, but I dont want it to be

Ok, so I get the error attached each time a client tries to pay, however, the objective is for us to charge their card "OR" their checking account. My form has both options, but when the echeck info is filled out andthey submit the error below pops up, the CC is NOT marked required, but we still get the error below.

How can I fix this please

attachment was too large: Error reads " Error during transaction cc # is required" 

To prevent your form from having an error, you will need to setup a multiple payment form. You can do so by setting up another form that will contain the Auth.net payment gateway and embed it to your main form using an iFrame embed widget. Please follow this guide to setup multiple payments: How to Create a Basic Multiple Payment form

Do let us know if you need further assistance.