lib/phoenix_admin/accounts/user.ex

phoenix_admin_accounts_error_handler.ex

# lib/phoenix_admin/accounts/error_handler.ex
defmodule PhoenixAdmin.Accounts.ErrorHandler do
  import Plug.Conn

  @behaviour Guardian.Plug.ErrorHandler

  @impl Guardian.Plug.ErrorHandler
  def auth_error(conn, {type, _reason}, _opts) do
    body = to_string(type)
    conn
    |> put_resp_content_type("text/plain")
    |> send_resp(401, body)
  end
end