I want to know how I could recover my lost worlds

pretend that I delete minecraft from my iphone to reinstall it (I did this so that it would be updated since my iphone works like that) then I started session with xbox as I always have done and when I want to get into my world it is no longer there
It should be noted that I had previously removed minecraft and recently installed it and the world that I had had for a long time was still there (it is the same account I have always used right now) and then right now my worlds are no longer there and I would like to know how recover them since they are very valuable to me