Package 'libapache2-mod-fastcgi' has no installation candidate code example
Example: libapache2-mod-fastcgi
wget https://mirrors.edge.kernel.org/ubuntu/pool/multiverse/liba/libapache-mod-fastcgi/libapache2-mod-fastcgi_2.4.7~0910052141-1.2_amd64.deb
sudo dpkg -i libapache2-mod-fastcgi_2.4.7~0910052141-1.2_amd64.deb