For Gathermate2 Classic
To enable Un'Goro Soil (and any others)
Navigate to the addon's location in the WoW Addons folder.
something like: C:\Program Files (x86)\World of Warcraft\_classic_era_\Interface\AddOns\GatherMate2
Then open the "Constants" file
CTRL+F: "Un'Goro" then remove the two dashes
--[NL["Un'Goro Dirt Pile"]] = 511,
to
[NL["Un'Goro Dirt Pile"]] = 511,
Then CTRL+F for "soil"
Remove the two dashes.