Where did you get that idea from?
Redirecting to a block page generally does not work as soon as HTTPS is involved.
Due to the increasing (and now almost complete) proliferation of HTTPS, Pi-hole has switched its default behavior to NULL blocking as early as 2018 with Pi-hole v4.0 , so that the block page was no longer used by default.
The blockpage itself was removed from Pi-hole in 2022, so about 3 years before v6 has been released.