Air France, Aeroflot, Martin Holland and Air Europa, which have returned from Cuba, have cancelled flights from Madrid to China. Multiplication is not recommended unless you want to be angry with the Air China agent at Havana Airport, who always makes trouble for people. Air France tickets are very expensive. If you want to save money, go to Aeroflot, whose office is in the business center, but Havana flies to Moscow only once a week. Recommend Martin Airlines to KLM, with high cost performance and good service attitude. Havana flies to Amsterdam two or three times a week, and Amsterdam flies to Beijing, Shanghai, Hong Kong and Guangzhou once a day. I flew back from this company. Martin Airlines also has flights in Valadero, which seems to run twice a week. The office is on 23rd Street, not far from the Ministry of Higher Education of Cuba.
It is not recommended to buy electronic tickets, but must buy paper tickets. Buying electronic tickets in Cuba may be very troublesome! In addition, don't forget to find a school to run PERMISO DE SALIDA for you before you leave, otherwise you can't leave even if you buy a plane ticket.
Sure enough, they are students, and I know your situation, so you can't leave the school. I don't know if your passport is in your own hand or in the school's hand. If the school has it, you have to get it back. But no matter who has it, you have to apply to the school, and let the school apply for a departure permit (that is, PERMISO DE SALIDA) for you to go to the immigration office, otherwise you can't leave Cuba at all. Then go to the airline office to book tickets. I remember I gave the address and phone number of Martin Airlines in the post bar before. You can look carefully in the post bar (you can find it by keywords) and call them to ask about the price and flight date. Then go to Havana to buy tickets. I'm afraid it's not possible to book tickets by telephone. I can only tell the school to buy tickets to get the opportunity for the school to go to Havana. When buying a ticket, tell the conductor when you want to buy a ticket to China (Beijing/Shanghai/Guangzhou/Hongkong), and the conductor will tell you when there are flights and fares. You can get the ticket when you pay. Use a passport, because the name and ID number on the ticket must be entered according to the passport. You can buy tickets by credit card.