Missing 'Use Windows session credentials' checkbox

Hello,

Maybe I'm missing something here but we are running 3 ESXI hosts without vCenter.  The Hosts are all running the free version of ESXI 6.5.  We are able to log into the web client just fine with the local root user as well as domain users with the username@domain.com syntax.  The issue is that the checkbox to 'Use Windows session credentials' isn't even there.  I've seen it grayed out or not work right but to be missing altogether??

Any guidance would be great.

Thanks,

Ernst.