You will need to login to mail.google.com with the
user name or google business email address ex. [email protected]
and the password for that account.
~ If needed, here’s instructions on how to reset the password for that user email. https://support.google.com/a/answer/33319?hl=en
Need help figuring out your google business email, logging in for the first time. We can help in a live video/screen sharing session. There is a charge for this. Alternatively, Google does provide support reps that can help you do this too (for no charge since you are paying them for this service.)