The Sony FDR-X3000 4K Action Cam supports 4K video recording but how can you play that video on a 4K TV?
Fortunately the back of the Sony FDR-X3000 4K Action Cam has a micro HDMI (Type D) connector that could be easily confused with the USB micro-B connector next to it.
You then need to get a micro-HDMI to standard HDMI cable like this one, AmazonBasics High-Speed Micro-HDMI to HDMI Cable - 6 Feet. The micro-HDMI plug connects into the Sony FDR-X3000 4K Action Cam while the standard HDMI connector connects into a 4K TV like the LG B6 OLED 4K HDR Smart TV - 65" Class.
After pressing the menu button on the Sony FDR-X3000 4K Action Cam, you then need to select the playback function on the top right square and you can start playing videos stored on the Sony FDR-X3000 4K Action Cam's SD card onto the 4K TV.
Note that even though the Sony FDR-X3000 4K Action Cam lets you select 2160p (4K) and 60p HDMI signal frame rates, the actual HDMI output is 4K@30fps since that is the resolution of the videos taken and only HDMI 1.4 is supported on the camera.