Niantic has announced that a Friends Referral System has been added to Pokémon GO and Trainers in Australia will be the first to receive referral codes that they can share with friends

Invite your friends to enjoy Pokémon GO and earn rewards together!

Trainers, We’re excited to announce that a referral program will soon be coming to Pokémon GO ! When you refer a friend to enjoy Pokémon GO—whether it’s their first time playing or they’re returning after a break—they’ll receive rewards like Pokémon encounters, Rare Candy, Incubators, and more as they hit milestones on their adventure—and so will you.

Like other features we’ve launched in the past, we’ll be tuning the referral program over time in order to make the process as easy and exciting as possible. Trainers in Australia will be the first to receive referral codes that they can share with friends. Stay tuned for more information as we roll out this exciting new program!

We hope that you enjoy playing Pokémon GO together!

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

UPDATE: 03/17/2021 - The Pokémon GO referral feature is now available to Trainers in Australia! Stay tuned for more information on when the feature will be available in your region.

Source: https://pokemongolive.com/post/referrals-launch/?hl=en