On ubuntu you open Software, search thunderbird, and click the install button. Or you open the terminal and type sudo apt-get install thunderbird.
How come you were able to learn how to do it by drag-and-drop on macOS, even though installing an application by D&D is completely unintuitive and unique to apple, but learning how to do it the linux way is an insurmontable task that you can't expect normal people to figure out?
How come you were able to learn how to do it by drag-and-drop on macOS, even though installing an application by D&D is completely unintuitive and unique to apple, but learning how to do it the linux way is an insurmontable task that you can't expect normal people to figure out?