Is it free to work abroad?

No, the state clearly stipulates that there are charging standards for labor services abroad:

According to the relevant regulations of the state, the expenses that migrant workers need to bear and not be refunded include medical examination fees, training fees, passports, visa fees, airport construction fees, vaccination fees, notarization fees, etc. According to the regulations, in the payment of these expenses, the physical examination can be carried out by hospitals at or above the county level or organized by operating companies. The expenses shall be paid according to the actual charges of the hospital, and a receipt shall be kept; The training time is at least 48 hours. According to the training duration, the training fee is generally between RMB 150 in 600 yuan (including the teaching material fee and the training certificate fee for the overseas laborers). Training fees are paid directly to the training center by migrant workers, and can also be handed over to the operating company. The training is organized by an overseas labor training center recognized by the operating company and qualified by the state.

If there is no charge, it is likely to be a black intermediary. You should go to the Ministry of Commerce to check whether the company is qualified!