Where To Start?...

const { SlashCommandBuilder, PermissionFlagsBits } = require('discord.js');
const Discord = require('discord.js');

module.exports = {
    data: new SlashCommandBuilder()
        .setName('slow-mode')
        .setDescription('Just Shut The F*ck Up Chat, Stop Spamming')
        .addStringOption(option =>
            option.setName('input').setDescription('Add Time Exmple: 10 (Max Seconds: 21600)').setRequired(true)),
    async execute(interaction) {

        if (!interaction.member.permissions.has(PermissionFlagsBits.ManageChannels)) {
            return interaction.reply({ content: 'You Need The `MANAGE_CHANNELS` Permission To Slow The Messages.' });
        }
        if (!interaction.guild.members.me.permissions.has(PermissionFlagsBits.ManageChannels)) {
            return interaction.reply({ content: 'I Need The `MANAGE_CHANNELS` Permission To Slow The Messages.' });
        }
        let slowmode = interaction.options.getString('input')
        interaction.channel.setRateLimitPerUser(slowmode).catch(() => {
            interaction.reply({ content: "Failed to set slowmode in this channel, check your slowmode length." })
        })

        let embed = new Discord.EmbedBuilder().setTitle(`JUST SHUT THE F*CK UP`)
            .setDescription(`**I have set the slowmode in ${interaction.channel.name} to ${slowmode} seconds! \nGo [Here](https://convertlive.com/u/convert/seconds/to/minutes 'Convert Live') To Convert These Seconds To Minutes**`)
            .setColor("#2F3136")
        return interaction.reply({ embeds: [embed] }).catch((e) => console.log(e));
    },
};