Sorry I cancelled my lesson last time without any notice.
Sorry I cancelled my lesson last time and I didn’t send you any message.
I finished work late and didn’t have time to send you a message.
1)’ 前回は連絡もせずレッスンをキャンセルしてしまいすみませんでした‘
without ~なしで
notice 知らせ、通知
cancel キャンセル、取り消し
last time 前回
2)‘前回は事前にメッセージも送らずレッスンをキャンセルしてすみません。’
3)‘仕事が遅くに終わって、メッセージを送る時間もとれませんでした’
late 遅くに、遅れて
"Last time I was unable to let you know in advance and had to cancel without giving notice."
"last time" 「前回」"Last lesson" や "the previous lesson" も使えます。
"I was unable to~" 「〜ができず」
"let you know" 「知らせること」
"in advance" 「事前」
"without giving notice" 「無断」
"Last time, I wasn’t able to let you know in advance, and I ended up missing the lesson without notice. I’m really sorry."
"Last time, I wasn’t able to let you know in advance, and I ended up missing the lesson without notice. I’m really sorry."
"I’m sorry for last time. I couldn’t message you beforehand, and it became a no-show."
"I apologize for the last-minute situation. Work ran over, and I couldn’t send a message, so I missed the lesson without notice.
1. 仕事が終わらなかった（work ran over / work took longer than expected）
2. 事前に連絡できなかった（I couldn’t let you know in advance / I couldn’t message you beforehand）
3. 無断キャンセルになった（I missed the lesson without notice / I was a no-show）
日本 
オーストラリア 
アメリカ合衆国 
