Are there any cloud computing platforms that require no credit card for the free service?

I've tried Amazon WS, Google Cloud Platform and Microsoft Azure, and though these sevices all have a free plan, all of them require a valid credit card info for the registration, which I sadly cannot obtain at the moment. I am a student, and I would like to use a VM (either Windows or Linux) to run longer calculations, but not immensely resource heavy ones.

Are there any other services similar to the three mentioned above that can be used without a credit card? Or is there maybe some kind of workaround for these?

Thanks in advance.