@amahlaka Since you wrote the expanded documentation I'm hoping you could help here?

It can be difficult to verify domain if you can't open ports 80 and 443 on your router, recommend way is to use DNS provider that allows you to create txt records, you can get domains like that from namecheap for under 1$

Hi @amahlaka and @Landrash,
Unfortunately, the answer above doesn't make instructions clearer.

1. Could you please elaborate more regarding ports 80 and 443? Do you mean port forwarding to set up encryption, e.g. using Let's Encrypt or something else? I did not mention that there is a problem to open ports.
2. I think that instructions for HASS do not mention paid DNS providers for text records. Is this way is more simple than to upload html for verification?? See here https://community.home-assistant.io/t/html5-step-getting-ready-for-chrome-pls-help/6586
3. My html5 push notifications work ok without this verification process. Is it really necessary step?

I've temporarily solved the issue on domain verification by adding the meta tag in \Python35-32\Lib\site-packages\homeassistant\components\frontend\templates\index.html however, I don't think that it is a good solution.
This step still needs clarification and some simple solution if its really necessary for html5 push notification.

It seems like the instructions in general could use an update, as it was confusing which values to use for the keys. It even looks like the API key may be deprecated going forward.

There was no action on this issue for over six months. I'm going to close it.