If you use Authorize.net or Stripe, you can enable bank transfer as a payment method on your Donation forms. You can also enable Salesforce integration for your Donation forms so payment data is sent in real-time to Salesforce.
If you have done so and you see that the Form of Payment field on the Lead and Opportunity object is not being populated for eCheck transactions, add the following as a picklist option to the Form of Payment field on both the Lead and Opportunity object:
Bank Transfer
Haven't enabled bank transfers in your payment processor yet? Check out these articles for guidance on that process:
Enabling Bank Transfers in Stripe
Accept bank transfers with the Donations app and Authorize.net