I Googled "how many computers can Camtasia be installed on" to be sure their policy has not changed. The following suggests you may have two copies of Camtasia or Camtasia Studio on two computers. Like a book, only one can be in use at a time. https://www.techsmith.com/volume-license-faq.html
If you uninstall you can put it on two others. There may be a need to go on-line to free up a license. That, I don't remember.