Where can I set the permission for the user that they need to have

[TFAGaming]

Sorry, but I didn't understand the title of this issue. Please provide more information!

[bogdanwebdeveloper]

In the module.exports you have a line where you can set the permisions needed.

[TFAGaming]

My bad, for slash commands, use the method .setDefaultMemberPermissions from the class SlashCommandBuilder. Here is an example:

const { PermissionFlagBits } = require('discord.js');

new SlashCommandBuilder()
   .setName(...)
   .setDescription(...)
   .setDefaultMemberPermissions(PermissionFlagBits.Administrator)

More info: https://discordjs.guide/slash-commands/permissions.html#member-permissions

Now for prefix commands, you need to use if keyword to check whenever the user has the required permissions or not.

const { PermissionFlagBits } = require('discord.js');

if (!message.member.permissions.has(PermissionFlagBits.Administrator) {
   // Your code here
};

[PassiveFr]

I know how that works but if the user doesn't have perms it will not display the slash cmd but I want it like that it sends an error embed instead

[TFAGaming]

It is similar to prefix command, but instead of message, it's interaction. Here is an example.

const { ChatInputCommandInteraction, SlashCommandBuilder } = require('discord.js');
const ExtendedClient = require('../../../class/ExtendedClient');

module.exports = {
    structure: new SlashCommandBuilder()
        .setName('')
        .setDescription(''),
    /**
     * @param {ExtendedClient} client 
     * @param {ChatInputCommandInteraction<"cached">} interaction 
     */
    run: async (client, interaction) => {

        if (!interaction.member.permissions.has(PermissionFlagsBits.Administrator)) {
            await interaction.reply({
                embeds: [] // <= Your embed
            });

            return;
        };

    }
};

[TFAGaming]

No response, closing...