As part of the computerization process of Cuban society and in order to facilitate visa applications, the Cuba Online Visa Application System began operating on February 9, 2022, on the platform http://visasonline.minrex.gob.cu/es
In the case of Mongolia, there is a bilateral visa-free agreement, so Mongolian citizens do not need to apply for a visa to travel to Cuba.
If you are Mongolian and are going to travel to Cuba to carry out professional or official activities, other than tourism, such as business, journalism, etc., you must contact the Embassy of Cuba in Ulaanbaatar to carry out the pertinent coordination.
In the following link you can find an audiovisual tutorial for your visa application for Cuba.