GM.listValues
From GreaseSpot Wiki
Description
This method retrieves an array of preference names that this script has stored. See GM_setValue for details on the storage of these values.
Syntax
function GM.listValues( )
Compatibility: Greasemonkey 4.0+
Arguments
None.
Returns
A Promise, rejected in case of error and otherwise resolved with an Array
of String
s for previously set values.
Examples
console.log(await GM.listValues());