Your URL is wrong and also you can configure the firewall. Try below URL. Configure port as describe below if you have not already.
http://jarvissqlvm.cloudapp.net/ReportServer/PageTo Connect to Remote Report Manager
Here are more detail steps.
If you want to connect to Report Manager on the virtual machine from a
remote computer, create a new virtual machine TCP Endpoint. By
default, the report server listens for HTTP requests on port 80. If
you configure the report server URLs to use a different port, you must
specify that port number in the following instructions. Create an
Endpoint for the Virtual Machine of TCP Port 80. For more information
see, the Virtual Machine Endpoints and Firewall Ports section in this
Open port 80 in the virtual machine’s firewall.
Browse to report manager using Azure Virtual Machine DNS Name as the
server name in the URL. For example:
Configure a Firewall for Report Server Access