Project management allows you to invite Any contact (prospect, customer, partner, supplier, etc.) to participate in a project.
To invite a contact, you have to create a contact record is Sellsy.
To send invites, choose add external contacts.
In the next window, you can check all, which lists the partners who will have access to the project:
Confirm who will receive an email to access the project in the lists you have made public.
At any time, you can check to see if a list is public with the icon on the left side of the column - if the eye is green, the list is shared with external users.