You can add board members and freely assign/change their roles when you have created a club in Unioo without a bank connection.
All of this takes place under "Settings" in the menu on the left when you're logged in to your account:
Assign/change roles
When board members are invited to create an account, you can already assign them a role at this stage. However, all board members can freely change their own roles under "Your roles" in the menu:
IMPORTANT! If the club was created in Unioo through a bank, changes to the role distribution must be done via a report. Read more about this here.