I am actually in a similar situation.
In my country, when I was 18yo, the military service was compulsory for all males.
However, you could postpone for college/university for study, family or medical issues; eventually at 26yo, you could serve or be exonerated (e.g. if the family or medical issues were still applicable). That was my case.
So, into the DS260, at the question if I had ever served in a military service, the answer was no, as I have never served.
When I sent the docs I did not include the exoneration papers, as they would just create unnecessary confusion.
KCC is not familiar with all military recruitment laws in the rest of the world. They expect the documents as per the reciprocity docs page and consistently with the DS260 answers.
However, CO is expected to be familiar with the local military draft rules, so I will just bring my exoneration papers at the interview and show them if requested.
So, I suggest you should obtain your discharge/exoneration military ticket from your country's military authority, and have it ready for the interview at the embassy, should they enquire about it.