/etc/security/pam_usb.conf

<agent event="lock">
<cmd>/usr/bin/mate-screensaver-command --lock</cmd>
</agent>
        <agent event="unlock">
<cmd>/usr/bin/mate-screensaver-command --deactivate</cmd>
</agent>

 sudo pamusb-agent

 Message: 17:22:04.163: Failed to connect to the D-BUS daemon: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11

mate-screensaver-command