Zoho Learn - External Users = Paid Users?

Zoho Learn - External Users = Paid Users?

Hi,

We are wondering if we could move our Ambassador Program to Zoho Learn. But currently, with our software, the company gets an access code, used by the staff to sign up and create their account, so we can see their completion.

If we were to do the same in Zoho Learn:
- Is there an easy way for people to sign and register for the course - knowing that this is for front-line staff of some companies (and shouldn't be open to everybody)?
- Would they be considered paid users when they are approved? 

Thank you.