There are no ebuilds to satisfy "x11-misc/sddm[elogind?]"

[kris 0]

Hi

I'm trying to install plasma-meta, but receive information
 

Quote

emerge: there are no ebuilds to satisfy "x11-misc/sddm[elogind?]" 

[ebuild   R    ] x11-misc/sddm-0.19.0::desktop-kit  USE="consolekit pam (-elogind) (-systemd)
-test" 0 KiB

How to add a USE-flag elogind, so I can change it

[cardinal 77]