Flavoured for a Debian 10 IPA-joined web server, and based on these pages from the FreeIPA wiki:
# Install pre-requisites
sudo apt install libapache2-mod-authnz-pam libapache2-mod-auth-kerb libapache2-mod-auth-gssapi
# libapache2-mod-nss isn't packaged for Buster for some reason, but oldstable package works fine: