@client.tree.command(name = "join", description = "Makes the bot join your voice channel.")
async def join(interaction: discord.VoiceChannel):

    try:
        if interaction.guild.voice_client:
            channel = interaction.guild.voice_client.channel
            await channel.connect()
            await interaction.response.send_message(content = "I joined the voice channel!")

        elif not interaction.message.author.voice:
            await interaction.response.send_message(content = "You have to join a voice channel to                    use this command!")
    except:
        await interaction.response.send_message(content = "I'm already in the voice channel, are you blind?")

I tried to find a youtube tutorial of how to make your discord bot join your voice channel using slash command but I couldn’t find any.