[nchmy]

> The Sec-Fetch-Site header can't be read / written by Javascipt

Perfect. It's not even meant or needed to be. The server uses it to validate the request came from the expected site.

As i and others have said in various comments, you seem to be lost. Nothing you're saying has any relevance to the topic at hand. And, in fact, is largely wrong.

[tankenmate]

"Nothing you're saying has any relevance to the topic at hand. And, in fact, is largely wrong."; your confidence in your opinion doesn't make you right.

Prove it.