Can we connect to the JSM Broker from an external application (Application from internet outside BPT) to consume messages generated by iFlows or publish messages to a queue so that iFlows can process them?

I have a REST API Integration flow, with XML as input (Request Body) with some schema, Some of the fields are numbers (integers or decimals). I need to return a Response body as XML and one of the field needs to be an arithmetic sum of two of the f...