https://12ft.io works on some sites through pretending to be the google bot.

You can also access any site in the google cache with prepending "https://webcache.googleusercontent.com/search?q=cache:", that will you show you the website like the google bot saw it.

For example github.com would become "https://webcache.googleusercontent.com/search?q=cache:https%..."

It is still worth to try, but many sites already prevent this.

Certainly at this point anybody serious about wanting to give Google special access through their paywall would allow based on the published IP blocks [1] and not an easily spoofed UA header

[1] https://developers.google.com/search/docs/crawling-indexing/...