Sometimes you will need to do this to be able to issue certificates and HTTPS is not enabled by default on the website.
Start IIS Manager, right-click Default Web Site and select Edit Bindings… Click Add and choose https in the dropdown. In SSL certificate, you need to choose a certificate that you have installed. If you haven’t installed a server certificate, you have to install it (I will post article on this later).
You should also, when Default Web Site selected, choose SSL Settings and choose SSL Required.
Now you should be able to access https://<servername>/certsrv.