getTime is undefined

                .setDescription(`**Username:** <@${user}> (${user_id})\n**Action:** User Joined\n**Joined At:** <t:${Math.floor(member.user.joinedAt.getTime() / 1000)}:F>`)

  <rejected> TypeError: Cannot read properties of undefined (reading 'getTime')
      at C:\Users\levit\Downloads\blonde\Events\Modlogs\guildMemberAdd.js:24:150
      at process.processTicksAndRejections (node:internal/process/task_queues:95:5)       
} reason TypeError: Cannot read properties of undefined (reading 'getTime')
    at C:\Users\levit\Downloads\blonde\Events\Modlogs\guildMemberAdd.js:24:150
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)