127.0.0.1/html has nothing to do with us. i don't know where that url come from but is not from this package config files for sure.
http://pi.hole/admin/ or http://<pihole_machine_ip>/admin/ or http://<localhost_127.0.0.1>/admin/ should work out of the box.
i think you'd better follow pi-hole ARCH wiki: https://wiki.archlinux.org/index.php/Pi-hole
Pinned Comments
max.bra commented on 2018-02-09 16:45 (UTC) (edited on 2019-10-18 23:14 (UTC) by max.bra)
ArchLinux Pi-hole is not officially supported by Pi-hole project. In case of bugs and malfunctions please DO NOT file a report upstream.
First of all check if the wiki (https://wiki.archlinux.org/index.php/Pi-hole) can help then ask here for assistance and tips.
When it will be excluded that the problem does not depend on ArchLinux we will file a bug upstream.