The submit event form in the backend no has so many information. Enabling them all on frontend submit form can make the form become complicated for frontend users (not admin), that's the reason we don't enable that field (and many other fields)
If you need it, you will need to customize some code to add the field. You can submit a support ticket sending us super admin account of the site and the link to the form so that I can ask my developer to modify code to add this field for you
Regards,
Tuan