I'm on this boat as well. It's June 2023 and was expecting I could sign him since I've qualified for the CL again after my first season.
Spurs have 2 buy options for him
https://www.theguardian.com/football/2022/mar/22/spurs-deal-with-juventus-to-buy-dejan-kulusevski-revealed
1. Optional buy clause for €30M throughout his 18 month loan
2. €35M mandatory buy clause that will be activated at the end of the 2022-23 season if BOTH conditions are met:
He plays 50% of the team's Premier League matches for at least 45 minutes
Spurs qualify for the CL