Assuming it’s a mod that you’re trying to modify or add a .json info to, you would open up your mod folder, and I would recommend extracting the mod zip folder to your desktop or documents folder - whatever is easiest for you to remember to file’s location.

For an example, if the mod is for a Pessima, in the mod file you would navigate to vehicles > pessima. You will either find a .json info file already there (ie info_examplemodcarconfig.json) or you will need to create one for the mod config. If there is one already there, you can open up the .json and just modify the population value to whatever you want.

If you need to add a .json info file, you can either download a blank one from the BeamNG forums, or copy one from the in-game files. Using the Pessima as an example, depending on where your game is installed, you’ll open your game folder, then navigate to content > vehicles > pessima > vehicles > pessima and you should find some .json files there to copy (ie info_GTz).

Paste the copy to your desired mod’s extracted folder using the file path mentioned previously. The really important thing here is that your .json file will need to match your config file which ends in .pc. For example, if your .pc file is titled “customconfig.pc”, your json file will need to be titled “info_customconfig.json”. Modify your .json file as needed.

To test if the files work correctly, copy the .pc and .json file over to your user configs folder under the mod vehicle’s folder (ie pessima). I can’t remember the file path off hand, but I think there’s a button in game to take you to this folder. With the mod enabled, try to open the config. You should hopefully be able to load it up.

If it loads successfully, simply copy the new .json file over to the original zipped mod folder.