If you mean that you want to setup an exposed business object to be the target of a call back URL, then this wouldn't be possible unless their call back URL can send SOAP requests.
The only way I can see this working (if the call back uses regular REST api calls), is to have some intermediary service that will translate REST to SOAP calls so that they can be served by your business object.
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James Man
Professional Services
Blue Prism
Asia/Hong_Kong
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