Note: I'm using v13 of "discord.js".

This is the command that I currently have:

if (command === 'check') {
    if (message.member.permissions.has(['KICK_MEMBERS'])) {
      let mentioned = message.mentions.users.first();
      let name = mentioned.username

      message.channel.send(`Account name: ${name}.`) 
      message.channel.send(`Account ID: ${mentioned.user.}`)

    } else if (!message.member.permissions.has(
    ['KICK_MEMBERS'])) {
      message.channel.send('You do not have permissions to do this command!')

    } else {
      message.channel.send('An error has occured while attempting to run the command.') 
    }   }

The let mentioned = message.mentions.users.first(); gets the mentioned user

This is how you say the command:

!check @Downrest

Okay, so here's my question. How do I get the creation date of mentioned?