Add BellSoft official GPG key and setup the repository
wget -q -O - https://download.bell-sw.com/pki/GPG-KEY-bellsoft | sudo apt-key add -
echo "deb [arch=amd64] https://apt.bell-sw.com/ stable main" | sudo tee /etc/apt/sources.list.d/bellsoft.list
Liberica JDK repositories contain all Linux architectures supported in the release: amd64, i386, arm64, armhf. If amd64 is not the target architecture, replace it in the command above with the architecture of choice.
Update repositories and install packages:
sudo apt-get update
sudo apt-get install bellsoft-java11
Reference