"The H-2A program allows U.S. employers or U.S. agents who meet specific regulatory requirements to bring foreign nationals to the United States to fill temporary agricultural jobs. A U.S. employer, a U.S. agent as described in the regulations, or an association of U.S. agricultural producers named as a joint employer must file Form I-129, Petition for a Nonimmigrant Worker, on a prospective worker’s behalf."
In order for a person to come to to the United States lawfully as a non-immigrant to work temporarily here, your prospective employer must generally file a non-immigrant petition on their behalf.