first you have to generate a CSR (Certificate Server Request) and submit it to a CA to get back the SSL certificate with the private key.
After that take a look at Installing SSL certificate on Sense server
Then if you already have the cert created, you will probably want to follow the directions listed in the post linked by Andrea Gigliotti.
I followed these steps. but no result.
"Received from domain CA certificate on the server. If not necessary to, I will describe how to do this.
further open the properties of the certificate, tab "details" option "Thumbprint"
and copied value as is, with spaces.
Edit Proxy, check Security and paste value in "SSL browser certificate thumbprint" with space.
Restart Qlik Sense Web Server"
you have to remove spaces in your Thumbprint string and then paste it in "SSL browser certificate thumbprint" under proxy settings.
after restart the Qlik Sense Proxy Service.