Not sure about the Leaf plus but the older Leafs had a large threaded bolt with an eye hook that you'd screw into the bumper by removing a plastic plug. My '13 came with such a bolt but I believe I've read posts of people looking to purchase one, so maybe they don't come standard anymore?
Oh there is a plug on the front drivers bumper and hook under the rear passenger bumper.
2012 SL purchased used 2/'16
2013 S w/QC purchased new
Juicebox Premium 60a L1/L2 EVSE, Ebusbar 16a L1/L2 EVSE
'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
Zencar 13, 20, 30a L1/L2 portable EVSE
GE Durastation 30a