Assign a custom Project Manager role automatically to a Project Manager user

Summary:

1.     The ‘Project Managers’ in Oracle Project Accounting only approve project expenditures

2.     When we add a new project and name a person as a ‘Project Manager’, Oracle automatically assigns the standard ‘Project Manager’ role

How can define that the system assign a custom "Project Manager" role ??

What are the privileges to "only" approve project expenditures?

Version (include the version you are using, if applicable):
B84628 - Oracle Fusion Project Financials Cloud Service Hosted Named User