You're seeing just the function leave, go back to SlackWeb.Channels module for more information.
Link to this function

leave(channel, optional_params \\ %{})

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Leaves a channel.

Required Params

  • channel - Channel to leave

Errors the API can return:

  • cant_leave_general - Authenticated user cannot leave the general channel
  • channel_not_found - Value passed for channel was invalid.
  • is_archived - Channel has been archived.