Unable to redeem my GCP credit

Hello,

I received coupon code for the Cloud Run Hackathon
but I cannot set up billing account due to error OR_BACR2_48 and payment
verification failure. I'm from Nigeria and this appears to be a regional
payment restriction issue.

Hackathon ends in 5 days, I'd be grateful if I'd be offered any form of assistance either in form of: Alternative coupon redemption method that doesn't require setting billing account or pre-activated billing account
I look forward to hearing from you.
Thanks