Be patient.
I think you will be flown here (in business class if available) and put up in a nice hotel for 2-3 nights.
Interview day is a presentation of the company and what to expect followed by an ATPL exam with 50 questions.
Followed by an interview. If all goes well, sim in the evening in whatever sim is available.
Make sure you research the company very well as you will be asked what do you know about Qatar Airways.
Regarding the sim, fly the aircraft, CRM and be yourself.
Good luck