Unfortunately, you can't turn that on as an administrator because the Intuit accounts your team members use to log in are owned and managed by each individual.  Manage Users merely creates a connection between your account and these individuals and assigns a certain level of access rights to each.

2FA must be turned on by each individual user at https://accounts.intuit.com.  Changes made here will affect not only their access to Lacerte under your account but also their access to other Intuit products associated with that particular email address.

As administrator, how do I confirm that all of my users turned on the 2 factor?