According to Wikipedia, only some of the episodes were aired in the U.S. and you can view them in the provided link to archive.org below. Interestingly, the YouTube channel VHS Junky has some of unaired episodes in the German language. Would anyone here happen to have any sources to obtain better copies of all of the episodes?
Sources:
https://en.wikipedia.org/wiki/Great_Scott!_(TV_series)#cite_ref-1