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

lookup_by_email(email, optional_params \\ %{})

View Source

Retrieve a single user by looking them up by their registered email address. Requires

Required Params

  • email - User's email address

Errors the API can return:

  • missing_scope - The token used is not granted the specific scope permissions required to complete this request. Need:
  • user_not_found - Value passed for user was invalid.