You can require admin approval for all users before they can enter.
Go to Setting > Security and enable User acceptance.
Optionally, you can automatically allow users from a particular domain, for example, your business email domain.
1. Users get a user acceptance message when they sign up for an account.
2. All admins get an email to accept the newly created user, and they can easily click the button in that email.
You can see in the user list if the user is approved or not. Also, you can accept the user directly there.
After the admin accepts, the user gets the below email so they know they can enter.