You may verify this document if you are eligible for a
public program. You may also verify if you can utilize free trial per this
document. As for methods of payments, there are
alternatives that you can check. Unfortunately prepaid cards and Virtual Credit Cards are not accepted. Though, debit cards might be accepted depending on the location. This is also a good
document about methods of payments that might help. For further help, you can also reach
cloud billing support, and assuming you already have a valid Cloud Billing account. I hope this helps.