How can a non-employee account be set up to be able to add an employee-type role via an API?

Summary: Need to be able to add employee roles to users via an API in an OIC integration via a user that isn't an employee.

Content (please ensure you mask any confidential information): Generally, users with privileges to add employee-type roles should be employees in role mappings; however, I do not want to use an employee account in an automated OIC integration. I also don't want to add a dummy-type user as an employee to production. Is there a solution for this?

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