How often should the Mijia Refrigerator Cross Door 510L's refrigerant be added?

If there is no leakage of refrigerant in the Mijia Refrigerator Cross Door 510L, there is no need to add refrigerant.
For your reference, here’s more information about the refrigerant:
1. The refrigerant is a chemical substance used in cooling systems, such as refrigerators and air conditioners, that absorbs and releases heat to help transfer thermal energy and maintain low temperatures;
2. The refrigerant of the Mijia Refrigerator Cross Door 510L is R600a. R600a, also known as isobutane, is a highly efficient and environmentally friendly refrigerant commonly used in modern household refrigerators.