my itunes

Hello. I own a MacBook M1 2020. I want to make a backup of my Iphone 11ProMax due to the fact that it has a very full memory and does not turn on. Recently I noticed that I can't update / install iTunes on my laptop because all the versions on the official sites have the following problem, I ask them to downgrade to my version of 12.4 Monterey and to move to version 10 Catalina. I would like to thank you in advance for your help and keep in mind that I really need it, thank you!