How to Submit a Form on behalf of a User
An Editor who has access to the form can edit the submission made by a user
Goto Left Menu >> Editor >> Forms >> View All Forms.
Select the form that you want to submit on behalf of a user and click on that form.
Click on Submit icon on the top right corner.
Click on the empty space below Select user to select the user you want to submit the form.
Enter the name to select the user you want to submit and fill in the details in the form and click on Submit icon to finish submitting the form.