If you have 2FA disabled on your account you need 6 digit code received via SMS to be able to sign in. If you are not receiving the SMS please check if the last few digits on the sign-in page match the last few digits of your telephone number.
If the number is correct, please wait a few minutes before repeating the sign-in, as the SMS sometimes comes with a delay. Also, please make sure you are able to receive the international SMSes.
If the number does not match, or the SMS is not received after a few tries please contact the support service.