Can we use the REST API to create/update suppliers using a service account?

Summary:

We have built an integration that uses external data and the REST API to create and update suppliers. We want to use a service account (that we use for all of our integrations) as the account the integration/API run under but it appears that in order to create and update suppliers via API, the user must be set up as a Procurement Agent and in order to do that, the user has to be an employee.

1. Is this correct that you have to be a Procurement Agent in order to create and update suppliers via REST API?
2. Is there any way we can get this to work with a service account so we don't have to have an integration running under an actual user (who could leave, change jobs, etc.)