You need an embassy visa for Armenia if you have a Djiboutian passport
Visa options for Armenia
Visitor visa
Travellers need a visa to visit Armenia for Business or Tourism. A paper or embassy visa is the only visa available for travellers visiting Armenia. The visa is typically a stamp or sticker added to the passport. Travellers must obtain this visa from a local embassy, consulate or visa center before travelling.
This is not offered by sherpa°.
Apply on the government site.