unable to approve forecast: error PJF-2236533 You don't have the required permission

Summary:

when the user that is approving the forecast is not the primary project manager the system returns the error "PJF-2236533 You don't have the required permission" .for the budget baseline we solved the issue following the note "You don't have the required permission. (PJF-2236533)". how to do the same for forecast?

the user has the Project Manager application role.if the user is assigned to "Project application administrator" or "Project Integration Specialist" it is possible to approve the forecast. we need to understand which privilege from one of these two roles is giving the right giving this grant. because we don't want to assign the entire role, the entire role provide to much access and grants. any suggestion?