Your debug log shows your lighttpd web server is not running:
*** [ DIAGNOSING ]: Pi-hole processes
[✗] lighttpd daemon is failed
You may test your lighttpd installation for syntactical correctness by running:
lighttpd -t -f /etc/lighttpd/lighttpd.conf
If that comes back with Syntax OK, try restarting it:
sudo service lighttpd restart
In case that fails, please provide the output for:
sudo systemctl status --full --no-pager lighttpd.service
All above commands need to be run on your Pi-hole machine.
EDIT:
Since you are running on Orange Pi, probably also check your ramlog ownerships as mentioned in Cannot access web interface - #8 by DanSchaper.