Once you have two files let Pythonanywehere know by using a "Send feedback" message (link at the top right of above linked page) where in your file storage on PythonAnywhere they can find the yourdomain.com.key and the yourdomain.com.combined.cert files, and which website it's for.
As per wiki article https://www.pythonanywhere.com/wiki/SSLOwnDomains, could you please activate the SSL cert for domain yourdomain.com.
Certs are located in /home/username (username.pythonanywhere.com)
If you ever need an urgent response, send an email to general support [at] pythonanywhere.com email.
From a Bash console on PythonAnywhere, generate the private key and CSR using the openssl command, like this (all on one line, replacing yourdomain.com appropriately):