I think you need to register with immigration and the local Board of Education to get a Tutor's license. It is not too difficult.
Korean American offering English lessons and essay review
I am a Korean American from Seattle with an F-4 visa. I am a native English speaker and I can speak fluent Korean. I graduated from the University of Washington. I was previously in the U.S. military and diplomatic service. I offer English lessons for adults and college students.