From the ‘Forms’ seccion, you have the possibility to lock forms. Locking works for deactivating the form, without the need to delete it and its work session. When you lock a form it will remain closed, it will no longer be accessible and people with the link won’t be able to submit.

To lock a form, click on the lock icon at the bottom of the form's card. To unlock the form, click on the ‘Unlock’ button on the top of the form's thumbnail.