Payed users versos collaborators

Dear sirs,
In our company we are considering to use Airtable pro.
But a question emerged.
We can have non payed users accessing via forms or kanban modes and giving inputs. Or will they be considered payed users?
The use case is the following, we are onboarding partners and organisations and we will establish a simple CRM to schedule our work. Some users will engage with the forms to get assignments and progress the leads. But the cost will not scale if they are payed users.

thanks in advance,