There have been many great comments pointing out that this was recorded in KiCad 6 and the latest release is KiCad 8. That's my mistake, but I have retested all of these plugins on the latest update and they all work as normal except for "Gerber to Order", which seems to be broken. In the mean time, until that plugin is updated, you can use "Fabrication Toolkit" for JLC PCB and it should work fine, even for other PCB manufacturers. There is an alternative called "PCBway fabrication toolkit" for PCBway, but seems this plugin has also broken during the update.
Another great plugin, although currently broken in v8 (in work), is kicad-action-scripts which includes a way to easily add thermal relief holes for your PCB.
When creating a set of gerbers for JLCPCB, do you still have access to their board population service? I have used that from Easyeda, but with that I can see what parts they stock.
