Can this be a solution for our clients to send us enrollment forms securely using a link that we send to them?

I think you were referring to this feature.

User guide: https://www.jotform.com/help/393-How-to-Attach-a-File-to-Autoresponder-Emails

You can attach a document/PDF on your form email so that the recipient will be able to receive the securely via the email.

Let us know if there is more we can help you with.