Impossible Sign-in Verification Issue

I am trying to log into my school email account associated with outlook. I have two-step verification on, even though I don’t remember setting that up. Anyway, the outlook in-app verification code has never worked for me and despite doing every trouble shooting method, the in-app verification code fails to work. So, I normally use my phone number to be sent a verification code. The problem is, my phone number changed, so I can’t receive a code. The solution to this is to change my phone number in the microsoft account, but to sign in, I require two-step verification, and without my phone number, the only option is in-app verification, which like I mentioned above DOES NOT WORK. I am going in circles and facing the same exact problem with absolutely no resolution, I tried calling U.S customer support, but they redirected me to their website because sign-in problems can only be resolved online. I tried recalling, but I guess they remembered my phone number and my issue and the automated bot will hang up on me after telling me to go online. The way that microsoft support website is impossible to navigate is so utterly annoying. I have wasted so much time going in circles online and I need to speak to a human, but microsoft is not allowing me to.