I want to sponsor a friend to immigrate to the United States. What visa does she apply for?

She doesn't unless she independently qualify for relief.  More information is needed.  Is she in the U.S.?  Does she fear persecution in her home country?  Is she from Ukraine? When did she arrive?  A U. S. Citizen cannot petition a friend as a matter of law. However, you can waste money and time trying to do this. A U.S. citizen can petition a fiance or spouse with enough evidence to prove that the relationship is in good faith, not just to get someone a green card. Otherwise, that is fraud and can lead to a permanent bar to lawful immigration.  A U.S. Citizen can seek labor certification from the Department of Labor for a potential employee, where they can afford to pay the prevailing wage, but any sort of employment based petition for a friend can prove extremely difficult and time consuming. I strongly recommend an appointment with a competent and experienced immigration attorney before there are any more complications.  This is general information, not legal advice, and does not create an attorney client relationship.