A referral code is a discount code that is used for existing Peyk users to refer their friends and family to get rewarded. Once the code is shared to a new user, both will get rewarded by Peyk.
Referral codes can be sent to new users at any time. However, once the code has been entered in the app, it will have an expiry of a month. So both the referee and referrer have a month to use their discount.