There are two ways forms can invoke this trigger. You can either select that every form sets off this trigger, regardless of the submission type, or that only a specific form sets off this trigger.
Note: If the form is used in QuickTickets or text modules using the placeholder [form.url], it is automatically replaced by the complete URL including the protocol. In this case, the rich text editors ask whether the URL should be created with a preceding "https://". It is essential to select "no" here, as otherwise the URL will contain the protocol twice.