interaction.options.getUser()

const userDiscord = interaction.options.getUser("user")

CommandInteractionOptionResolver {
  _group: null,
  _subcommand: 'daily',
  _hoistedOptions: [
    { value: '364726576656678912', type: 6, name: 'user' },
    { value: '', type: 3, name: 'item', focused: true }
  ]
}