This page of the Horizon 2 Forbidden West game guide explains what to do with the Hunting Medals received from the Hunting Grounds trials. You will learn where to find the Prize Master and the types of rewards you can get for the medals you earn.
Obtaining hunting medals
Hunting Medals are rewards for completing Hunting Grounds trials - we've described all Hunting Grounds trials in a separate chapter in our World Atlas.
Information about the medals you have obtained will be displayed at the end of each trial, i.e. on the summary screen along with the other rewards. The better you did in a given challenge, the more medals you will receive.
Finding the Prize Master
You will only be able to exchange your hunting medals for rewards after you have completed the Kulrut main quest. You need to return to The Memorial Grove.
The Arena is adjacent to the main part of the grove. Dukkah and Kalla are standing at its entrance. You need to accept the Opening the Arena side quest, which involves obtaining unique ingredients from the machines from the in-game world.
Completing the Opening the Arena side quest will not only unlock the option to fight in the arena, but also the option to meet with Dukkah the Prize Master.
Exchanging medals for prizes
After talking to Dukkah, a trade menu will pop up and the available options include exchanging your hunting medals for unique equipment - weapons, outfits and their upgrades. You can find out how many medals are necessary to purchase a given item in its description. As the items are quite expensive, you should only choose weapons or outfits that are especially useful and much better than your current equipment.
Dukkah also offers to exchange arena medals for items. Unfortunately, you won't be able to purchase them with hunting medals.