From CD Projekt RED:
Gamers wishing to check out GWENT on PlayStation 4 will have an opportunity to do so starting Friday, March 31st, 19:00 CEST. The Technical Beta will end Monday, April 3rd, 09:00 CEST. The game will be available for download from PlayStation Store.
More information about the Technical Beta is available in the official FAQ.
About GWENT: The Witcher Card Game
In GWENT: The Witcher Card Game, gamers clash with their friends in fast-paced duels that combine bluffing, on-the-fly decision making and careful deck construction. The game is played over a best-of-three series of rounds, as players unleash their hand by slinging spells and diverse units with special abilities and use clever tricks to deceive their opponents.