HTTPS is enabled in WidePath, when you click the 'Secure Mode' tab then 'Generate Certificate' button.
As long as you have entered all your hostnames into WidePath, and then pointed them correctly from your DNS provider, then click the 'Generate Certificate' button, there is nothing more to do.
If you make a mistake and need to add or remove domains, then you can always just click the 'Generate Certificate' button again at anytime. A new certificate will be registered that includes all your domains.
Note that on the secure tab, all your domains are listed along with a green check or red X. The green check means that you've correctly pointed your name and that the certificate registration process can complete successfully. But if you see a red X, the entire process will fail and you won't be able to get any certificate at all. So make sure you correct all the red X problems before you click 'Generate Certificate'.