put
https://api.seismic.com/engagementpermission/v1/engagements//collaborators
Update one or more existing collaborator role assignments on an engagement, such as changing a user from Viewer to Editor, when you need to adjust access levels without deleting collaborators or changing the Owner. Example: use this to change user-987 from Viewer to Editor on engagement 123e4567-e89b-12d3-a456-426614174000.