Use this Gojek Beta Sign up Promo Code if you don't have a DBS card but still want to enrol in beta.
Just tried. Says "Seems like this promo code is fully redeemed or invalid."
I tried putting the code in as a promo code. It's not supposed to be a promo code.
I believe when you first download the app and register, it will ask you for an invite code, which is where you put DBS + first 6 digits of your DBS card - or this code, as an alternative, it seems.
Gojek is now apparently available to everyone (not just DBS), as per an email I received from them this morning.
Bring on the promo codes, Grab!