Checkout button text on a giving form

Open Online Giving → Campaigns or Online Giving → Forms, select the campaign or form, then go to Giving Experience → Form Settings & Display → Display. Choose the relevant Pre-Payment Form, Payment Form, or Post-Payment Form settings; older interfaces show those as separate tabs.

In Pre-Payment Form settings, edit Form Button Text, up to 20 characters, and save. The standard checkout uses this or Go to Checkout. A default-payment-method path can instead show Donate Now; preview the actual flow.