#from https://ubuntuhandbook.org/index.php/2021/03/oracle-java-16-released-install-ubuntu-20-04/
apt install software-properties-common
sudo add-apt-repository ppa:linuxuprising/java
sudo add-apt-repository --remove ppa:linuxuprising/java
#and there your java
sudo apt-get remove oracle-java16-installer