You can start PhotoLine from an USB-stick without any problem. First you have to copy the installed PhotoLine folder from your hard disk to the USB-stick. Now you can start PhotoLine from the USB-Stick, but the settings are still saved to the hard disk. In order to fix this, you have to create a folder named "PhotoLineSettings" on your USB-stick. On Windows this folder has to be directly in the application folder, on macOS it can be either in the application package in "Contents/Resources" or in the application packages's folder.
If PhotoLine finds "PhotoLineSettings" on starting, it will read and write its settings to it. Of course it must not be write-protected.