yes it can. What you need to look for in the documentation is Chapter 21 - Domain-Specific processes .
Typical workflow would be to
- create custom Work item definition, which would then represent a node in your bpmn definition, which would call the external service. Work Item definition only answers the 'What' question.
- create custom Work Item handler, which would include the logic for this work item definition, typically in its execute method this handler would call some external service, handled the response and complete the current task, optionally providing some output. Work Item handler answers the 'How' questions.
I find this section quite well documented, the real examples are present. It should help you to get started.