Check out example codes for "how to display server count on discord.js". It will help you in understanding the concepts better.

Code Example 1

module.exports.run = async (client, message, arguments) => {
   const guild = client.guilds.get("566596189827629066");
   setInterval(function () {
      var memberCount = guild.members.filter(member => !member.user.bot).size;  
      var memberCountChannel = client.channels.get("626462657817477131");
      memberCountChannel.setName(`${guild.name} has ${memberCount} members!`);
   }, 1000);
};

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