Hi Ruslan.
There is no general answer to that. It really depends how you design the boundaries of your systems. So yes, it could be that you have an own microservice, that handles the policy application and owns a workflow that probably orchestrate the other services. It could also be that the quote microservice owns that workflow as you decide it is responsible for the quoting until the quite is really checked out.
The relationship of the BPMN and microservices is a “simple” service invocation/integration. So the application workflow might either call some quote service (or possibly also send a message, but POST looks you are targeting REST), not really knowing that there is a workflow in the background.
After all it is “simply” about how you organize your components/microservices, which might influence team structure and a lot of other things. To be honest it is quite hard to get this right in the first place - but it is pretty good that you give it a proper thought.
Hopefully this helps a bit further?
Best
Bernd