It enables Xbox Game Pass Ultimate and PC Game Pass members to give up to five friends a free 14-day PC Game Pass trial.
Friend referral invitations can sent from here or accessed via the Game Pass home screen. Players must be new to Game Pass to redeem the offer.
Microsoft fully launched the PC version of Game Pass in 40 additional countries last month.
Ravenlok (Cloud, Console, and PC) will join the service on May 4, ahead of Weird West: Definitive Edition (Xbox Series X|S) on May 8, Shadowrun Trilogy (PC) on May 9 and Fuga: Melodies of Steel 2 (Cloud, Console, and PC) on May 11.
Last week, the UK’s Competition and Markets Authority said it was blocking Microsoft’s $69 billion merger with Activision Blizzard due to concerns about its impact on the future of the cloud gaming market.