Modeller > Work Types > Edit work type > Participant Roles > Click the arrow at the end of the row or Actions > Configure

Select the Role Permissions nav bar

Set the permission:

• No will not grant the permission to holders of this role
• Yes will grant the permission to holders of this role. Where this role is assigned to a team, all members of that team will be granted this permission.
• User only will grant the permission to holders of this role, but only where the role is assigned directly to a user. When the role is assigned to a team, the members of that team will not be granted this permission.
• By phase allows you to specify a variation in the permission grant depending on what phase the work item is in.  When you select By Phase the phases for that work type display - you can then set the permission for each phase.