Assign User to Form when Creating with an option a Prefix code

Assign User to Form when Creating with an option a Prefix code which would serve as an assignment when uploading media would be automatically assigned before the name, to be able to filter by the Prefix and sort in a folder with Happyfile. Example Create Form User: user-001 Prefix: user-001 when attaching Media Video: user-001-videocat.mp4 image: user-001-dog.png File: user-001-cars.doc etc. This Prefix option that came for the other fields. They are necessary when you enter a link in the button for email and telephone to be used on mobile. If the client enters his telephone number 592898765 when assigning the url of the button, it does not work if he does not write tel:592898675 with the automatic prefix within the form client enters telephone number: 50246629346 the form would save tel:50246629346 in the url. and it would work just like email: mailto:youemail.com.