If you have set up a 'form submitted' trigger, and upon testing you see in the trigger history screen that it is not firing, please check that the action aligns with what is required for a blank form or a prefilled form:

Blank forms: if the form you are pointing the trigger at is a blank form, the action must be set to 'Send notification'. (Remember, notification emails remain in the Compose Email folder once sent, they do not move to the Sent folder)

Prefilled forms: if the form you are pointing the trigger at is a prefilled form, the action must be set to 'Send email to matches'

 

This is also outlined in the 'Form Submitted' section of the 'Triggers for standalone & Interaction' article.

 

If you have checked the action that is selected and confirmed it to be the correct one, but still see the trigger is not firing as you would expect it to, please reach out to your CSM or raise a ticket to Technical Support.