user_session_controller.ex

...

def new(conn, _params) do
    render(conn, "new.html", error_message: nil)
end

def create(conn, %{"user" => user_params}) do
  %{"email" => email, "password" => password} = user_params

  if user = Accounts.get_user_by_email_and_password(email, password) do
    UserAuth.log_in_user(conn, user, user_params)
  else
    render(conn, "new.html", error_message: "Invalid email or password")
  end
end

def delete(conn, _params) do
  conn
  |> put_flash(:info, "Logged out successfully.")
  |> UserAuth.log_out_user()
end
  
...