You can disable a payment method on a donation form by following these steps below:
Sign in to your Donorbox account and click the edit icon by the campaign you wish to update.
Click the 'Amounts' link underneath the 'Your Donation Form' header.
To enable or disable a payment option on a campaign, simply check/uncheck the credit card or PayPal checkbox to add or remove this payment method from a donation form. Be sure to click the orange 'Update' button at the bottom of the page to save your changes.
Hit the update button and you're set!