Function not found of the BO while calling from workflow agent

Summary:

I've defined a function called search PO line. Added the REST APi from specification. The same REST API working from Postman whereas while calling the function from Workflow Agents, getting error message function not found.

I've attached the BO definition and the error message coming that function not found where while calling PO function it is working fine only for child restAPI call it's throwing error function not found.

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