TKL is a simple content management system using XML/XSLT. The LOT software uses that to produce (most of) the content. You can get the TKL software from http://www.indexdata.dk/tkl/.
Install the TKL software by simply un-taring in /var/www/html :
cd /var/www/html sudo tar zxf tklite-version.tar.gz ln -s tklite-version tklite
After unpacking modify ownership of the TKL files to the same user as Apache. On RedHat 8 that is user=apache, group=apache, so you could do:
sudo chown -R apache.apache /var/www/html/tklite
Enable TKL in PHP/Apache by creating the file /etc/httpd/conf.d/tklite.conf with the contents:
AcceptPathInfo On AddHandler tklhandler .tkl Action tklhandler /tklite/shell.php DirectoryIndex index.tkl
Restart the web-server to make these changes take effect:
sudo /etc/rc.d/init.d/httpd restart