Does "I didn't have practice" not work?
You technically wouldn't say 연습이 없었습니다. You would say, 연습을 안했습니다, to show that you didn't or haven't practiced.
Korean commonly omits subjects. "I haven't practiced" should also be acceptable.
The subject here is "The practice", watch how 이 is after 연
We have not hit past tense verbs if you are still before Written or Verbs2.