Online check-in Aero Mongolia - https://www.check-in.site

As of my last training cut-off in September 2021, I can't provide specific instructions for online check-in with Aero Mongolia as these processes can vary widely between airlines and may change over time.

Generally, here's how you would check in online for most airlines:

1. Visit the official website of the airline (in this case, Aero Mongolia).

2. Look for an option labelled "Online Check-In", "Web Check-In", or similar. This is usually found in the main navigation menu or within the "Manage Booking" or "Passenger Services" sections.

3. After selecting this option, you will usually be prompted to enter details of your booking. This may include your booking reference or ticket number and your last name.

4. Follow the on-screen instructions to complete the check-in process. You might be given the option to choose your seat, and you may also be able to print out your boarding pass or have it sent to you via email.

Online check-in generally opens 24-48 hours before the scheduled flight departure time and closes a few hours before the flight. The availability of online check-in can depend on factors such as the specific flight and the departure and arrival airports.

Please note that not all airlines offer online check-in, and the specifics may have changed or differ slightly since my training data. Always refer to the most recent information provided by Aero Mongolia on their official website or contact their customer service for accurate and up-to-date information.