Hi bboystyle20, thank you for asking here in the Community. Let me provide you with some insights on this topic.
While the Affirm payment option is not yet live, once implemented, it will be available to eligible businesses in the U.S., whether the account is new or already established, as long as it meets the eligibility criteria.
You can read more about this feature in this article: About Affirm payments.
Don't hesitate to reply here if you have more questions.