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.