No. Camtasia is sold for Windows and Mac only. On Linux you record the screen with OBS Studio and edit the result in a video editor, which is two apps instead of one.
Camtasia by TechSmith · Video · No way to run it
TechSmith's download page offers Windows and Mac. There is no Linux version, and no browser version either.
What Camtasia did so well was put screen recording and editing in one window, with the tutorial-maker's
toolkit built in: callouts, zoom and pan, cursor highlighting and quizzes. Nothing on Linux bundles all of
that. You will be splitting the job in two.
Recording is the easy half. OBS Studio is free, has an official Linux version and records the screen and your
microphone to a clean video file. It is the tool streamers use, so it is more than capable, though the first
setup screen is busier than Camtasia's record button.
Editing is the other half, in Kdenlive or Shotcut. You get cuts, titles, transitions and audio, which covers
most of a tutorial. The specific Camtasia touches are the gap. Automatic cursor zoom, animated callouts and
quizzes all have to be faked by hand or dropped. If they were the reason you bought Camtasia, that is a real
loss and worth weighing before you switch.
A simpler editor for straightforward trim-and-title tutorials, and less to learn in the first week.
Your files: Cannot open Camtasia projects. Edits the recorded video files directly.
This doesn't have to stop you
One stubborn program doesn't have to decide the whole question. You can keep Windows on the same PC and restart into it only when you need Camtasia. Everything else you do can move.