From Guild Wars 2 Wiki
Provisioner Tokens are a currency earned by trading in various rare level 80 crafted weapons and armor to Faction Provisioners in various zones in the Heart of Maguuma. They are stored in the Account Wallet and can be spent at the Faction Provisioners. At most, 12 Provisioner Tokens may be earned daily per account.“
Earned by helping Factional Provisioners in the Heart of Maguuma.
— In-game description