I can't seem to get realms to show up for my account on my Java version

I am very confused on how the realms works, I have Java on PC and then on Xbox and IPhone, I have a realm I pay for name Azeluna that I am trying to get working on PC as my Xbox has broken and I have finally been able to afford a pc to keep playing this great game. I just bought the Java version today thinking realms went across all versions? If not I'd like a refund as I spend hundreds of hours on Azeluna