Hi Marina

The number of attempts for the SCORM is controlled by what the  SCORM package  definition of an attempt is. The SCORM needs to have a status of 'completed' 'passed' or 'failed' for a new attempt to be enabled. 

There is some discussion on this here https://moodle.org/mod/forum/discuss.php?d=332285

SCORM is designed to allow multiple re-entries into the same single attempt. It is up to your SCORM package to define when an attempt is finished. Then the SCORM spec states that we need to let the user re-enter the old attempt in "review mode" or allow them to create a new attempt.

More info here:
https://help.totaralearning.com/display/TL10/SCORM+troubleshooting#SCORMtroubleshooting-HandlingofMultipleAttempts

regards