Executing STD API from custom schema

Hi All,

Hope all are doing well.

We got a requirement to execute STD API  PO_CHANGE_API1_S.update_po  (to update quantity in a BPA release line) from a custom schema.

We can successfully able to execute the STD API from Apps schema, but we are facing below errors when we execute it from custom schema.

Note: we cannot register it as a concurrent program as the STD API will be called from middleware webservice by means of a procedure only

l_result: 0

Failed to update the Release qty Due to Following Reasons

l_api_errors-count IS 4

Oracle error -942: ORA-00942: table or view does not exist