When we need admin rights to do some stuff on Ubuntu 18.04, we are prompted with an Authentication Required window, asking for a sudo-account's password.
My problem is that it seems we can't choose which sudo-account we want to use.
This is a problem because my users are supposed to use a specific sudo-account to install some softwares, but the only one they can see when prompted for sudo-account, is the IT-account.
Is it possible/How to have the drop-down menu like there was in Ubuntu 16.04 ?
PS: I know this is a duplicate of this, but there is no answer for months.
Edit: Ok, let's assume that a drop-down menu is not possible. Is there a way to change the default account which appears ?