Bulb most likely burned out..
could be a grounding problem make sure you have a good connection in that taillight
You might need another taillight if that don't work you might need to see a mechanic.
Open the liftgate Remove the 2 screws at the top of the taillight assembly Carefully " work " the taillight straight back towards you . There are plastic pins shaped >>>>>>>>>>>> that hold the taillight assembly in place The bulb sockets are a simple turn to remove / install
take it to the shop as soon as possible.
Open the tailgate.Remove the taillight bolts, pull taillight toward you to release two clips.Unplug the taillight connecter.Connect the taillight connecter.Install the pushing away from you to fasten the two clips.Install the taillight boltsClose the tailgate.
Check the "taillight" fuse in dash. If it is good, check the connector behind the back bumper for broken wire or dirty connector
Open tailgate. Remove 2 torx screws in side of taillight. wiggle taillight out, Remove hex screws that hold bulb assembly in taillight. change bulb, Reassemble
Taillight shark was created in 1966.
taillight is one word.
wrong taillight bulb is possible the bulb was recently replaced check to see if it has the correct application part#.
There is a taillight fuse in the fuse panel.
Open the lift gate , remove the ( 2 ) screws at the top of the taillight , carefully work the taillight straight back towards you ( it has plastic pins >>>>>>>> that hold it in place and you don't want to break any of those ) The bulb sockets are a simple turn to release