When you set up your account on evee, you will have a referral code generated for you. To find your referral code please first sign into your evee account and go to My Account.
Use your code to invite friends who aren't on evee yet. They'll get A$25 off their first trip. Once they complete their rental you'll get $25 AUD, too.
For more information about how to use your code properly please have a read of your evee's Referral program Terms and Conditions.