WithThe first DLC, Ashes of Ariandel, introduced dedicated PvP arenas -to the game: Undead Match - were introduced into game.
Undead Match is accessible from the bonfire in Firelink Shrine, but you need to acquire Champion's BonesChampion's Bones and burn them onin that bonfire first.
Champion's BonesChampion's Bones are obtainable in the following DLC locations: either from killing Champion's Gravetender & Gravetender Greatwolfthe Champion's Gravetender & Gravetender Greatwolf boss in Painted World of Ariandel or after completing Lapp's quest line in the Ringed City DLC but(but only if you don't own the first DLC).