apobj = apprise.Apprise(debug=True, asset=apprise_asset)

    # Override Apprise's built-in Discord plugin with our custom one
    # This allows us to use colored embeds for diff content
    # First remove the built-in discord plugin, then add our custom one
    apprise.plugins.N_MGR.remove('discord')
    apprise.plugins.N_MGR.add(NotifyDiscordCustom, schemas='discord')

The schema (discord://) is already defined and could not be loaded from custom notify function discord_custom_wrapper.