As always, I think we need to know more context before we can provide an answer that makes any sense. There are many ways that things can be delivered.
Are you hosting (uploading the files) to this client's server? And then it is reporting data back to SmartTracker with xAPI? If that is the case, your client may need to whitelist:
If you're hosting the lesson on SmartTracker, you shouldn't need to do anything. And if you're not using SmartTracker, and using xAPI to communicate with a different (non-SmartTracker) LRS, then domains/ports above won't help - you'll need to get that information from that LRS.
Hopefully that helps!