Log in to the server. Go to “Users and permissions” as illustrated in the image below.

Click on the user you wish to inactivate/disable on the server and uncheck the box “Enabled”.

The user is now disabled.
Log in to the server. Go to “Users and permissions” as illustrated in the image below.
Click on the user you wish to inactivate/disable on the server and uncheck the box “Enabled”.
The user is now disabled.