The match that will take place at Tottenham's home ground is decisive because they can achieve a bigger victory if they are able to take advantage of the conditions. Tottenham did not play badly in the first leg, it's just that they were unable to create chances to score because even though they had several chances, Tottenham had problems in the finishing stage. The momentum of playing at home must be used by Tottenham and they must not take it easy if they don't work hard to get the win.
I also assume so because in the first leg Tottenham played with a higher level of ball possession and AZ Alkmaar only won because of one own goal so that it was just luck for the home team in the first leg. As for the second leg I think Tottenham will try with maximum ability in order to win with a higher score and be able to qualify for the next round to compete again in the last eight of the Europa League this season. And I am quite sure that Tottenham will not underestimate their opponents at home because being behind by one goal in the first leg is still quite possible for Tottenham to reply in the second leg.
What's the use of possession if we don't create anything from it and Tottenham didn't even get many chances in the first leg. From the game implemented by Ange Postecoglou in the first leg, it can be said that he lost in tactics with AZ Alkmaar which made Tottenham's game deadlocked and not develop in the game.
So in the second leg Ange Postecoglou must make a major overhaul because certainly in the second leg AZ Alkmaar will play a defensive game only relying on counterattacks, because their position is already superior on aggregate. Of course if Tottenham's game is as slow as the first leg I'm not sure Tottenham can qualify for the next round even though they are playing in front of their own supporters.
So the solution is Tottenham's strategy must be changed in the second leg and the game must not be slow. Tottenham must be able to play through the midfield in empty spaces plus control the ball, and players must be proactive in moving and running into empty spaces so that they can create many opportunities to score goals.