Detailed below are the procedures that I used to install VirtualBox 7.2.0 onto Linux Mint 21.3. The officlal VirtualBox website has all of these instructions on it and was used as a reference. This is just a cleaned-up version of those instructions and what worked best for me.
Because I want VirtualBox to automatically update with the rest of the system, I will need to tell the system's package manager where to get all of the files.
Before adding the repository, I add the authentication key in order to avoid an error message.
Open the command line Terminal. Enter the following command to download and register the authentication key. If it nothing appears (like the command locked-up), enter your user password to continue. Sometimes the password prompt isn't displayed.
wget -O- https://www.virtualbox.org/download/oracle_vbox_2016.asc | sudo gpg --yes --output /usr/share/keyrings/oracle-virtualbox-2016.gpg --dearmor
You can now exit the terminal.
Open the Software Sources program. Go to the Additional Repositories section and select Add. Put the following line in and then clock OK.
deb [arch=amd64 signed-by=/usr/share/keyrings/oracle-virtualbox-2016.gpg] https://download.virtualbox.org/virtualbox/debian jammy contrib
At the bottom of the window you will see a message saying that your configuration has changed. Click on the OK button to update the APT cache.
You can now close the Software Sources window.
Open the Synaptic Package Manager. Find the package "virtuialbox-7.2" and mark it for installation. (It may say that additional chages are required, just click on Mark to accept.) Click on the Apply button to proceed with the installation.
Once the installation is complete, you may close the Synaptic package manager.
Go the the VirtualBox Downloads page. Riight-click on Accept And Download, select Save Link As to download the extension to your computer. (Just clicking on the Accept And Download button will display the contents of the file instead of downloading it for some reason.) Once it is downloaded, navigate to the file and double-click on it. This should automatically launch VirtualBox and ask if you want to install it. Click on the Install button. Read through the license and click on the I Agree button. You will be prompted for your password to allow the installation to continue. After a few seconds the install should complete and you will be at the main VirtualBox screen. You may now close VirtualBox.
In order to use the VirtualBox Exntensions (e.g., USB devices), you will need to add your user to the VirtualBox group
In the Applications menu, under Administration, open the Users and Groups program. You will be prompted for your password. After, select your user name and then click on the list to the right of the Groups label. A new window should appear. Look for the "vboxusers" entry and enable it. Click on the OK button to confirm the select and close the Users And Groups window. Now reboot the system.
After the reboot, VirtualBox should now be ready to go.