I don't think it will create the target folder for you. Did you try this -
function OnStart()
{
app.MakeFolder( "/sdcard/Extracted" )
app.UnzipFile( "yourfile.zip", "/sdcard/Extracted" );
}
Note: on a scoped storage device (Android 10+) "/sdcard/*" paths will point to the /Android/data/[packagename].... path