I want to mail the Zoho form to 200 people (the user has consented to the email). I want to send the form to them with the email or some other unique identifier from my database (in this case from Zoho recruit) prepopulated. I can add ref in the form URL, but I don't know how to add ref dynamically with each email

The purpose of this is when the form is submitted then I want to validate that the form was submitted by the person to whom the form was sent. (These people are outside my organization)

Also, I want to avoid every time the same user goes through the steps of verifying email for submitting the form. I hope I am clear in stating my need.