You gain the ability to heal yourself. As a Bonus Action, you can roll your Martial Arts die. You regain a number of Hit Points equal to the number rolled plus your Wisdom modifier (minimum of 1 Hit Point regained).
You can use this feature a number of times equal to your Wisdom modifier (minimum of once), and you regain all expended uses when you finish a Long Rest.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.