The “DAYS OF FLAME” scenario.

After completing the "Days of Flame" map with a hero, I noticed that I forgot to complete a quest: finding the magical quiver (I found the bow). I searched the ENTIRE map, but I couldn't find it. There is no one left on the map except for the warlocks on the island in the right part of the map (they killed the elven archers and took over their castle). The map tells the story of how Tieru became a dragon knight and an exile due to a demon's betrayal. (For those who played it but forgot). I would be grateful for any help.

This is an official map, included in the game... Patch 3.1.