I was able to share my screen on my LG TV.
Details
TV Model: LG 43 LJ617 T
WebOS 3.60.10
Windows 10 64 bit OS
My TV and laptop are connected to the same wifi.
On my TV. I went to Home screen>>Device Connector>>PC>>Screen Share>>Miracast>>Start
Then TV goes to Screen Share mode and leave the TV like that
Now I go to my Laptop>>Action Centre(Right bottow on windows 10)>>Connect
The TV gets listed there. I click on the TV name and the connection is done. The screen share is complete.