The LG G4's micro USB port uses the SlimPort adaptor standard. To connect to an HDTV, you will need a SlimPort adaptor and seperate HDMI cable.
Note: Some Settings, Menus, or Icons may differ from that of your device depending on your software version and wireless service provider.
Connect your device to the SlimPort adaptor.
Note: SlimPort may require a power source. Please refer to manufacturer for instructions.
Finally connect the HDMI cable to your HDTV and SlimPort adaptor.
You will need to change the input of your HDTV to the correct HDMI input.
Note: Some SlimPort adaptors are made for specific devices. Check that the adaptor you purchased is compatible with your device.