Ich vermute, es ist Amazon gemeint.

I did avoid them for a long time. Once I started to figure out how to self certify for https NPM became very helpful. DNS challenge does not require you to open any ports. you need a domain that supports dns challenge, though. Pointing cname to local ip of reverse proxy. And some routers may require rebind protection entry for that domain. Afterward: https and nice names for all my local only services.