How to block majestic and ahrefs bots in nginx or robots?

Question

Nginx

How to do this effectively (I read that they can ignore robots)? And is it okay to block it at the nginx level (not robots.txt)? What is needed for this, user agent? Where to find him?

Answer 1

Yes, you are right, this really requires the User-Agent of the bots.
For nginx configuration:

if ($http_user_agent ~* (AhrefsBot|majestic) ) {
    return 403;
}