Question Help Gmail account


Jun 19, 2019
Good day!

I opened one google email account where I can use more users. I think I opened it over (2FA) or (2-step) or the like ... I do not know exactly! I am the founder, and the rest are only users who have received a second password from Google, they all use. This looks like their password: rpufzxemojozyoyv
They mostly send emails through this account, which is good. It is only important for them to send mail, it does not matter to receive mail. All this works well and I'm very happy.
- But I want to block some users because they have this password and are not our users. They also send mail in various places and abuses through this account.

How can I block them so that I can no longer send mail via our account? Is it possible, which option do I use, what should I do?
Please help me to solve this!