I also noticed the missing java8 version… so took the plunge and upgraded my RPi java version like this…
wget https://github.com/bell-sw/Liberica/releases/download/11.0.2/bellsoft-jdk11.0.2-linux-arm32-vfp-hflt.deb
sudo apt-get install ./bellsoft-jdk11.0.2-linux-arm32-vfp-hflt.deb
And then simply used the existing server file… seems to work just fine for me.