Translation of "confirmation" into Japanese

Please let me know the confirmation number you were told when you reserved the room.

予約の際に聞いた確認番号を私に教えて下さい。

When I began to study with Jehovah’s Witnesses, I was also preparing for my confirmation as an Anglican.

エホバの証人と研究し始めた時,聖公会の堅信礼を受ける準備もしていました。

Huan was delivered to me, confirming the appointment I had just made on the telephone.

それは先ほどの電話による約束を追認したものでした。