Referenced variables in markdown do not appear when exporting to other format like HTML

Dear all

I have created a jupyter notebook and now tried to export it to other formats like HTML. My problem is that I have markdown cells with references to variables (with {{}}). When I export it does variable values do not appear. I tried almost everything for hours without any success. I found the following amongst others:

But still I can not manage to do it. Could somebody give me an easy step-by-step explanation what I need to do?

Thanks a lot,