里昂機場Rhonexpress的E-ticket - 自助旅行

請問一下有人有用過Rhônexpress的E-ticket嗎？
因為買E-ticket沒有比較便宜，但是好像可以免去排隊的麻煩，
不過我有一個問題，他的網頁有提到E-ticket

This E-Ticket is not your final ticket. When boarding the tram,
present it to the Rhônexpress steward, who will give you your
final ticket and register it at the same time.
This registration is equivalent to validating your ticket. All
tickets, regardless of type, must be registered by the steward.

請問這段的意思是說我可以直接搭車，然後在車上看到steward，
在把e-ticket給他註冊？還是我必須在搭車之前就先去找steward註冊？
謝謝大家

--