SOAP Web Service to download attachments for Fixed assests

Summary:

When I tried to call soap service to download Fixed attachments then I got this error.

"JBO-Request Failed : Reason- User did not supply correct user key: Request Failed : Reason- User did not supply correct user key.oracle.apps.fnd.applcore.messages.FndMessagesUtil$FndMapResourceBundle"

I'm Passing

ENTITYNAME as "FA_ADDITIONS"

CATEGORYNAME as "FA_SUPPORTING_DOC"

User Key A as Asset_Number.

Where can we get the which parameters require to download the FA attachments.

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