Easy peasy! Just share your invite link, which can be found via these places in the app:
Tap Share Invite Link to copy your referral link and share away!
Alternatively, you can use the last part of your unique invite link to be used as a promo code (e.g. TEST123)
Note: You need to have an active Burpple Beyond membership plan to be able to refer and enjoy the rewards. Your referral code is only valid for first-time Beyond members signing up for an All Day (Monthly or Annual) plan.