Bounties cannot be started freely like normal quests. First, check the sighting information for each bounty, then take on quests matching the listed Rank and Type. A bounty may appear when one of those requests is added to the Quest Board. If the bounty’s Stock is 0, you cannot challenge it yet. Once you obtain Stock, select the bounty and choose a Threat level to begin the battle. The Bounty system is unlocked after clearing a Rank A quest for the first time.