Score calculation in questionnaires

Hi, I am having trouble making my questionnaire tally scores of drop-downs. I see examples online and on the Loinc website (LHC-Forms Demo) but how is the extension added to generate this functionality?

I have managed to work with decimal fields but for scoring I am unable to recreate what is shown for the 5M Apgar Score.

Is it possible to get the full JSON for loinc forms with the extended functionality?