In the settings of the scorm activity in moodle, you can set “Auto-Continue” to “Yes”. This makes moodle continue with the next AU when the previous one has been finished. The action in Lectora to move on to the next AU is “Exit title / Close window”. You’d have to make the first a prerequisite of the second in Lectora.
This should work when you open the course in the same window.
If you open the course in a new window, the window is closed, but when the user opens the course again, it will display the second AU (if the first has been completed / passed / failed).
Of course I don’t know what you’re trying to achieve, but normally I’d advise to use two separate courses with one AU each and use moodles conditions to make the second available when the first has been finished.