@Deyan,
$ sed -e 's,groovy,focal,' /etc/apt/sources.list | sudo tee /etc/apt/sources.list.d/focal.list $ sudo apt-get update && sudo apt-get install linux-oem-20.04b
@Deyan,
$ sed -e 's,groovy,focal,' /etc/apt/ sources. list | sudo tee /etc/apt/ sources. list.d/ focal.list
$ sudo apt-get update && sudo apt-get install linux-oem-20.04b