This worked. I am using lighttpd. For those with a similar issue. I checked to see which users existed, as @DL6ER said the default user for lighttpd is www-data. I confimed by checking the /etc/passwd file that the user existed and added the user to the pihole group.
usermod -a -G pihole www-data
^^ will add the pihole group to the www-data user. You will need to use this command with an elevated account or with sudo.