Install java jre on a newly installed system

I just installed Alpine Linux in a VM on a disk. (alpine-setup, set the only virtualized disk to sys). Now I want to run Java: pkg add openjdk8-jre says unsatisfiable constraints? Note this is x86 architecture and I have my reasons for that. Thanks for any help! I searched on the wiki installation and checked packages if this package exists for this architecture but found nothing.

The mirror I selected was something like dl8.alpinelinux.org (something what had 8 instances of it, each with its number)