Ssl standalone app (Apache)

I need to install a standalone ssl webapp in Apache.

the server is configured as follow:
ssl port 443
Apache listening on port 443

in Apache there are already 2 active cgi application:

this configuration cannot be changed and I have no other ssl ports available.
my standalone Xojo ssl application (e.g. built on port 8080) must be available under Apache (so on the same port 443) as:

I apologize if I don’t expose well.
I am not Apache expert.
moreover my customer does not give me technical support.

has anyone had similar experiences and can help me?

i think its called Reverse Proxy.
your given url https://myserver/app3 is translated to any intern (intranet) ip:port by a config.
the advantage is your intern apps do not need https behind the apache.

without this if you start the apps there it would look like