For the next month you can train Kuriboh for the chance of getting a Prismatic SR/UR Choice Ticket. (The Ticket appears to be limited to UR/SR provided by the various characters in Duel Links)

Duel regularly to evolve your Kuriboh.

Ranked and Special Duels grant more points.

The ultimate aim is to get Kuribohrn and the Prismatic Ultra Rare/Super Rare ticket.