Having bought flight tickets from a third party, how do I check-in online?

I bought a round-trip flight ticket from a third party. The flights are operated by Air France and China Eastern Airlines. More specifically:

Toulouse --> Paris --> Shanghai (operated by Air France) --> Fuzhou (operated by China Eastern Airlines)

Is it possible to check in online in advance?

I tried to check in on Air France, but I don't know my ticket number:

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How do I check-in for a third party flight?

Call the third party, and ask. Also the third party usually (but not always) give you the ticket number. If they do not, you can always get it from the airline by telling them the confirmation number.

What do I do if I bought a plane ticket online?

After you've selected your flight online, you'll be prompted to pay with a credit or debit card. The screen will then present you with your payment confirmation receipt, your eTicket, and your itinerary. Many travelers print the eTicket and itinerary or make sure they're saved together in their email for easy access.

How do I board a flight with online ticket?

Some airlines will make you pay a fine if you haven't checked-in online or if you don't have a printed copy of your boarding pass.

Buying Flight Ticket Online (10 MISTAKES + Google Flights tips)

Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.

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