I do not have documentation in French, sorry.
When you click each of the ‘Set Target’ buttons, the software reads the current position of the laser and assigns that position to the target that you have selected in the UI. When both target positions have been set, the ‘Align Output to Targets’ option will be automatically set and you will see ‘Ready (Print and Cut mode)’ in the status window above the laser buttons.
You must be connected to your laser for this to work, and jog the laser to the correct printed target on the object you are engraving on before clicking the ‘Set Target’ menu item. You must have two different targets at two different locations. Are you doing this?