All of these universal wall mount brackets listed on the page below are compatible with LG 55UJ6540 55" 4K UHD TVs. All Star Mounts carries various types of mounting bracket solutions such as flat (fixed position), tilting and articulating (full motion, pivot, swing).
LG 55UJ6540 wall mount bracket requirements:
Fit VESA 300x300mm mounting holes on back of the TV
Support 35.3 lbs (weight without stand)
TV dimensions: 48.7" x 28.3" x 2.5"
Note: As always when attaching a bracket to the wall make sure that the structure attaching the wall plate to can handle the load being applied to it based on the wall mount style you choose to purchase.