The sample application is called Dynatrace Orders. A more detailed overview can be found here. All the source code can be found here.
To get the Public IP, open the EC2 instances page in the AWS console. On the newly created host YOURNAME-dt-orders-monolith find the Public IP as shown below.

To view the application, paste the public IP using HTTP NOT HTTPS into a browser that will look like this:

Use the menu on the home page to navigate around the application and notice the URL for key functionality. You will see these URLs later as we analyze the application.
customer/list.htmlcustomer/5.htmlcatalog/list.htmlcatalog/searchForm.htmlorder/list.htmlorder/form.html