At present, we use the standard version of MSP. Because the approval process of MSP is not free enough, we consider to integrate the approval of MSP into the OA system for processing: that is, after the MSP submits the service request to be approved, we integrate the service request into the OA system, and after the OA system completes the approval, we feedback the approval status to MSP through the REST API. But we have a problem. When we call the approve interface of the REST API, we need to provide the key of the technician. Because the approver may not be the technician, but the requester, we will make the following errors when we use the key of any technician: 

Please help.