Require pre-payment information

Open Online Giving → Campaigns or Online Giving → Forms, select the campaign or form, then go to Giving Experience → Form Builder and select the appropriate Pre-Payment Form or Post-Payment Form.

In the form builder, add/select the appropriate pre-payment field, edit it and set Required to Yes, then save and preview the donor flow. Address components and phone are separate fields; requiring one does not require all the others. Use the editor for the intended form version and check the donor experience before publishing.