Open your form from the Forms page and click Edit. The Edit tab is the form canvas; Preview lets you try the form without recording a real submission.
Add a field
Click Add a field below the last field.
Choose a field type.
Use Field settings to set the label, help text, choices, and where the answer saves.
Click Done, then Save to save the form.
Available types are Short text, Long text, Email, Phone, Address, Dropdown, Single choice, Checkbox, Number, Date, Paragraph, and Static image. Paragraph and Static image display information; supporters do not answer them.
Edit a field
Click the field on the form to open Field settings.
Change its Label or Help text (optional). For Dropdown, Single choice, or Checkbox, enter Options (one per line). Leave a Checkbox field without options for a single checkbox.
Choose Saves to and set Required if supporters must answer.
Click Done, then Save.
Choose where an answer saves
Contact: First name, Last name, Email, Phone, or Address — map an appropriate field type to a contact detail. The choices depend on the field type.
Custom field — enter a custom field name to save the answer on the contact.
Answer only (not saved to the contact) — keep the answer with the submission only.
Use the up and down arrows to move a field, or the trash icon to remove it. Save the form after making changes. Keep field labels distinct so their saved column names do not conflict.
Keep the required email field
Every published form needs a required Email field mapped to Contact: Email. Publishing is blocked if that field is missing. The builder may let you change the field while preparing a draft; restore the required mapping before publishing.