Docker Desktop doesn't install saying docker-ce-cli not installable

In an online training course, the instructor mentioned that he has "an Ubuntu virtual machine installed with Docker Desktop"; therefore, I am trying to install the same on a Windows 10 physical host following the [instructions](https://docs.docker.com/desktop/linux/install/ubuntu/#install-docker-desktop) on the official website. However, the `apt-get install` didn't work, and the error message was `docker-desktop : Depends: docker-ce-cli but it is not installable`. I am wondering whether I missed anything here. **Screenshot:** ``` root@dockeru:/home/work/Downloads# ls docker-desktop-4.8.1-amd64.deb root@dockeru:/home/work/Downloads# apt-get install ./docker-desktop-4.8.1-amd64.deb Reading package lists... Done Building dependency tree... Done Reading state information... Done Note, selecting 'docker-desktop' instead of './docker-desktop-4.8.1-amd64.deb' Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help resolve the situation: The following packages have unmet dependencies: docker-desktop : Depends: docker-ce-cli but it is not installable E: Unable to correct problems, you have held broken packages. ```