To hide form fields, go to the Form Editor, click on the field that you want to hide and, in its Edit Field panel, tick the box Hidden. Although still visible in your Form Editor, hidden fields can’t be seen by form users.
This feature is especially useful when combined with the prefilled form fields feature. They allow you to receive reference information in form submissions and to keep this information hidden from users.
Note: Do not use hidden fields for conditional form logic. If hidden, fields won’t show up on your form at all. For branching and conditional logic, set up field rules in the Settings → Rules → Field Rules section.