Need admin access of all the supplier accounts for a dummy Supplier

Summary

Need admin access of all the supplier accounts for a dummy Supplier

Content

We have a client requirement where the client wants a dummy supplier account which can have access to all supplier's POs, Invoices, etc.

Currently, suppliers with its own supplier portal can post invoices of its own POs. But the client wants that we create a Dummy supplier account for them through which they can start posting invoice of all the suppliers from one supplier portal account only.

Is there any role or privilege which we can add so that we can arrange this for the client?