Be my guest: https://normativ.kontur.ru/document?moduleId=1&documentId=453093#h31

I know Russian and I have read the law, full text is available on the government site.

Don’t be, as Torrentfreak is not reliable source. Screenshot of the law on their site is about measures, similar to GPDR in Europe.

Law about external auth services is talking only about all these login buttons like login with Google, with Apple, or Facebook.

It is not required to use service (it’s Russian e-government service, pretty useful). There are still several options (yes, there is VK com, Russian “Facebook”). And it does not explicitly forbids plain old account creation with an email.