In Ubuntu 18.04 when installed using the Ubuntu Software Manager, it is installed as a snap. You can find it at /snap/sublime-tex/current/opt/sublime_text Yet when using snap, subl should be in your path already.

How do I open sublime in Ubuntu?

Type : subl in terminal to launch Sublime Text 3 from terminal.

How do I know if sublime is installed?

To check version, go to Help –> About Sublime Text .