Just an FYI, WebUI v2 (what you currently have) is still the current recommended version. You might want to hold off until you get the rest of your machine calibrated.
No firmware update. You just need to backup the files on Flash, delete all of those except the config.yaml file, and then upload all the files here (except you can keep your config.yaml file).
FluidNC_Configs/LowRider CNC/UI V3 LRCNC at main · V1EngineeringInc/FluidNC_Configs
If you run into issues or just don’t like v3, you can just restore your old files and you should be back to where you started.
Then you can get the extension here. It has the instructions on how to add it.
ESP3D-WEBUI-Mods/Extensions/JoyJog at main · jeyeager65/ESP3D-WEBUI-Mods
This is my thread on the topic:
WebUI v3 Extension - Virtual Jog Joystick - Software / Firmware / Jackpot Board / FluidNC - V1 Engineering Forum
You’ll see that I have a dark theme which I also created. There are some extension scrolling issues I haven’t figured out how to fix yet with the newest WebUI v3 but I’ll get there.