How to use the cogs.utils.config function in Cogs

def __init__(self, bot):
        self.bot = bot
        self.splat2_data = config.Config('splatoon2.json', loop=bot.loop,
                                         object_hook=splatoon2_decoder, encoder=Splatoon2Encoder)
        self.map_data = []

        self._splatnet2 = bot.loop.create_task(self.splatnet2())
        self._authenticator = bot.loop.create_task(self.splatnet2_authenticator())
        self._is_authenticated = asyncio.Event(loop=bot.loop)

        # mode: List[Rotation]
        self.sp2_map_data = {}
        self.sp2_shop = []
        self.sp2_festival = None
        self.sp2_salmonrun = []

        self.prefixes = defaultdict(lambda: list(config.command_prefix))

def get_voc_emoji(vocation: str) -> str:
    """Given a vocation name, returns a emoji representing it"""
    vocation = str(vocation)

    emoji = {"none": config.novoc_emoji, "druid": config.druid_emoji, "sorcerer": config.sorcerer_emoji,
             "paladin": config.paladin_emoji, "knight": config.knight_emoji, "elder druid": config.druid_emoji,
             "master sorcerer": config.sorcerer_emoji, "royal paladin": config.paladin_emoji,
             "elite knight": config.knight_emoji}
    try:
        return emoji[vocation.lower()]
    except KeyError:
        return "❓"

server in [s.id for s in user_guilds]]
        else:
            display_name = f'@{user.display_name}'
            embed.colour = user.colour
            if ctx.world:
                user_tibia_worlds = [ctx.world]
        embed.set_thumbnail(url=user.avatar_url)
        characters = await DbChar.get_chars_by_user(ctx.pool, user.id, worlds=user_tibia_worlds)
        if not characters:
            embed.description = f"**{display_name}** has no registered characters here."
            return embed
        characters.sort(key=lambda c: c.level, reverse=True)
        online_list = [x.name for k, v in online_characters.items() if k in user_tibia_worlds for x in v]
        char_list = []
        for char in characters:
            online = config.online_emoji if char.name in online_list else ""
            voc_abb = get_voc_abb(char.vocation)
            if len(characters) <= 10:
                char_list.append(f"[{char.name}]({char.url}){online} (Lvl {abs(char.level)} {voc_abb})")
            else:
                char_list.append(f"**{char.name}**{online} (Lvl {abs(char.level)} {voc_abb})")
            plural = "s are" if len(char_list) > 1 else " is"
            embed.description = f"**{display_name}**'s character{plural}: {join_list(char_list, ', ', ' and ')}"
        return embed

def get_voc_emoji(vocation: str) -> str:
    """Given a vocation name, returns a emoji representing it"""
    vocation = str(vocation)

    emoji = {"none": config.novoc_emoji, "druid": config.druid_emoji, "sorcerer": config.sorcerer_emoji,
             "paladin": config.paladin_emoji, "knight": config.knight_emoji, "elder druid": config.druid_emoji,
             "master sorcerer": config.sorcerer_emoji, "royal paladin": config.paladin_emoji,
             "elite knight": config.knight_emoji}
    try:
        return emoji[vocation.lower()]
    except KeyError:
        return "❓"

    "world": {"title": "🌐 World", "check": lambda ctx: ctx.guild.id not in config.lite_servers},
    "newschannel": {"title": "📰 News channel"},

def __init__(self):
        super().__init__(command_prefix=_prefix_callable, case_insensitive=True, fetch_offline_members=True,
                         description="Discord bot with functions for the MMORPG Tibia.")
        # Remove default help command to implement custom one
        self.remove_command("help")

        self.users_servers = defaultdict(list)
        self.config: config.Config = None
        self.pool: asyncpg.pool.Pool = None
        self.start_time = dt.datetime.utcnow()
        self.session = aiohttp.ClientSession(loop=self.loop)
        # Dictionary of worlds tracked by nabbot, key:value = server_id:world
        # Dictionary is populated from database
        # A list version is created from the dictionary
        self.tracked_worlds = {}
        self.tracked_worlds_list = []

        self.prefixes = defaultdict()

        self.__version__ = "2.4.0"

for member in guild.members:
            if member.id in self.bot.users_servers:
                self.bot.users_servers[member.id].append(guild.id)
            else:
                self.bot.users_servers[member.id] = [guild.id]
        # Update database member list
        async with self.bot.pool.acquire() as conn:
            async with conn.transaction():
                # Make sure there's no leftover data that will make the copy query fail
                await conn.execute("DELETE FROM user_server WHERE server_id = $1", guild.id)
                records = [(user.id, guild.id) for user in guild.members]
                await conn.copy_records_to_table("user_server", columns=["user_id", "server_id"], records=records)
                await conn.execute("INSERT INTO server_history(server_id, server_count, event_type) VALUES($1, $2, $3)",
                                   guild.id, len(self.bot.guilds), "add")
        # Show opening message
        message = f"Hi, I've been added to this server. Some things you should know:\n" \
            f"‣ My command prefix is: `{config.command_prefix[0]}` (it is customizable)\n" \
            f"‣ You can see all my commands with: `{config.command_prefix[0]}help` or " \
            f"`{config.command_prefix[0]}commands`\n" \
            f"‣ You can configure me using: `{config.command_prefix[0]}settings`\n" \
            f"‣ You can set a world for me to track by using `{config.command_prefix[0]}settings world`\n" \
            f"‣ If you want a logging channel, create a channel named `{config.log_channel_name}`\n" \
            f"‣ If you need help, join my support server: ****\n" \
            f"‣ For more information and links in: `{config.command_prefix[0]}about`"
        try:
            channel = self.bot.get_top_channel(guild)
            if channel is None:
                log.warning(f"{self.tag} Could not send join message on server: {guild.name}."
                            f"No allowed channel found.")
                return
            await channel.send(message)
        except discord.HTTPException:

def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.pool: asyncpg.pool.Pool = self.bot.pool
        self.session: aiohttp.ClientSession = self.bot.session
        self.yes_no_reactions = ("🇾", "🇳")
        self.check_reactions = (config.true_emoji, config.false_emoji)