Kindle library not syncing

I just booted up my kindle for the first time in years because I wanted to use it to read my external reading assignment. I’ll have to upload the file to my kindle so I downloaded the kindle app on my ipad and found that the library on my paperwhite is not showing up on my ipad (it says library is empty), I checked that I used the same amazon account so I’m just confused why it’s not showing my library.