The requester email isn't valid error in dropship Po creation

Summary:

We are getting below error when Dropship requisition/PO is creating from sales order. What could be the reason?

Please note that we have preparer setup in OM parameter and also order creation ID having it in Manage user.

Error:

The requester email isn't valid. It must be a valid email account associated with a worker with an active work relationship.

 

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