{
    "languageUrls":
    [
        "https://raw.githubusercontent.com/redbluegames/unity-mulligan-renamer/staging/Assets/RedBlueGames/MulliganRenamer/Editor/Resources/MulliganLanguages/en.json",
        "https://raw.githubusercontent.com/redbluegames/unity-mulligan-renamer/staging/Assets/RedBlueGames/MulliganRenamer/Editor/Resources/MulliganLanguages/pt.json"
    ]
}
{
    "languageUrls":
    [
        "https://raw.githubusercontent.com/redbluegames/unity-mulligan-renamer/staging/Assets/RedBlueGames/MulliganRenamer/Editor/Resources/MulliganLanguages/en.json",
        "https://raw.githubusercontent.com/redbluegames/unity-mulligan-renamer/staging/Assets/RedBlueGames/MulliganRenamer/Editor/Resources/MulliganLanguages/pt.json",
        "https://raw.githubusercontent.com/redbluegames/unity-mulligan-renamer/staging/Assets/RedBlueGames/MulliganRenamer/Editor/Resources/MulliganLanguages/es.json"
    ]
}

Add Spanish language to Language Bookmarks file
Add Spanish language to Language Bookmarks file

Without a link to the es.json, the Language updater can't find it.