It's a pretty simple program that rewards players by reporting bugs. However, it should be important to note that whoever discloses the bug first gets the credit for bug report. Once the bug has been verified by the team you receive an "acknowledged" on your bug report. It only takes 3 of these to get your reward and rewards are distributed every other Friday. What seems to be the reward right now is a homage to one of the older bugs R6S had, which was the raptor legs bug. This little thing is awarded in the form of a Frost charm which is pictured below.
The Bug Hunter Program will be initiated on the test server on April 25th 2019 and will remain active until further notice. Unfortunately, all reports received before then will not count towards the rewards. Ubisoft/R6S will keep everyone updated via their forum and their sub-reddit page on the new rewards available and other information regarding The Bug Hunter Program.