Can I apply to my father for a green card to come to the United States at the age of 20?

My son is 20 years old and can't apply to his father for a green card to come to the United States.

American immigration law stipulates that green card holders can only apply for immigration for spouses, minor children and adult unmarried children, and parents, brothers and sisters are not allowed to apply.

The way parents immigrated to the United States:

Get a green card.

Apply for naturalization and be accepted as an American citizen.

Apply for parents' immigration.

A green card is a permanent residence permit for foreign citizens. Holding a green card means that the cardholder has the permanent residence in the issuing country, and at the same time, holding a green card can exempt entry visas for a certain period of time.