Your Tomcat server is has been configured to serve as a web server. You have access to the back-end Linux server. But you do not know what directory corresponds with the URL of the host. How do you find what the default directory is for files that are presented on the web?
From the back-end, run this:
sudo find / -name index.html | grep tomcat
Look for a WEB-INF or webapps directory. See if there are subdirectories after one of these directories until the index.html file (e.g., /var/lib/tomcat9/webapps/foo/index.html ).