See here, they have an article about this: https://support.kraken.com/articles/360026925951-how-to-transfer-authenticator-app-sign-in-2fa-to-a-new-phone-and-bypass-sign-in-2fa-for-a-lost-phone-

I'm guessing you didn't setup a master key, nor did you keep the recovery key for the 2FA so right now, your best bet would be to contact the support.