Handling expired session in Phoenix

I want to know how to prevent this error which I get for requesting an expired session. What could be a good way to do that? I checked Custom Errors and Error Handling but not sure how helpful they are. Error message below.

ArgumentError at GET /svr/email/verify
cannot perform Monitor.Repo.get/2 because the given value is nil

lib/ecto/repo/queryable.ex
defp query_for_get(repo, _queryable, nil) do
  raise ArgumentError, "cannot perform #{inspect repo}.get/2 because the given value is nil"
end

Ecto.Repo.Queryable.query_for_get/3

• First, a UUID is created and set in the session.

  uuid = SecureRandom.uuid
  SessionStore.set uuid, id, ttl: 20
  

• Then below URL link is sent to the user and when the user clicks, it should check if the UUID is expired in session or not.

  <% verify_url = MyAppWeb.Router.Helpers.email_url(MyAppWeb.Endpoint, :verify, uuid: @uuid) %>
  

• UUID is checked

  def verify(conn, %{"uuid" => uuid}) do
    user_id = SessionStore.get(uuid)
  end