Estimate the term for setting up integration with a third-party site

If this is a request to the developers, I recommend that you draw up a more extensive and specific technical task, because the current one does not give an understanding of what needs to be done in full.

We have a logistics company that works with this site (this is a website), where it is looking for cars for transportation. Those. the client’s request for transportation enters the box, we create a BP in the box, at a certain stage of the BP we must transfer information about the client’s order to this site, the site automatically generates a shipment to the client (+ a car is selected for the client), and a number is generated to track the client’s order . This is the number we must pass to the box.
When we received the number, we are waiting for delivery, and from this site, when the delivery is completed, information that the goods have been delivered should be transmitted to the box, the transaction in the box is closed.
The main task is to implement a refinement so that we can precisely collect data from this site.

What methods should be used and in what order can you provide a description?

Does it take some time or do you get the number right away?
To understand whether we can organize all requests with the existing action "Submit a business process to the API" - it can process the response and write to the process.

API transfer.
We do not receive the tracking number immediately, employees will have to carry out manipulations on this site. Those. we have to request information constantly from this site (crones per minute). Also with the fact of delivery of goods.