Can+how do I use/host .Net core API?

Can I use .Net Core? If so, how do I host and get the certificate?

Challenge: Timestamp Microservice

Link to the challenge:

There’s no special restriction, as long as the project has an endpoint and returns the right things, then it doesn’t matter what is used to power it. FCC uses because that site provides an IDE that allows interactive development, and a way to easily deploy apps developed using it.

Re .Net Core, I assume Azure has a free tier you could use (& it works cross platform, doesn’t need IIS, so AWS, GCL etc should all have things that you can deploy to on their free tiers).