I need some Azure credits to continue playing around and building new stuff just to see how it works. Does anyone have any suggestions about how I could get some for free or very cheap?

I've already signed up everyone in the family for a free trial. I really can't ask friends because you need to provide credit card details. I know we've talked before about Microsoft programs that you can pay to subscribe and get some credit and I'll look into those.

Any suggestions? Is it possible for someone with some extras to sell it to me?