To enable HTTPS for the Web client, SSL has to be enabled in IIS for the Change Auditor application under the Default Web Site. Select the Change Auditor application and then double-click SSL Settings under ChangeAuditor Home | IIS. Place a checkmark in the option Require SSL.
For more detail about How To Set Up an HTTPS Service in IIS please review:
https://support.microsoft.com/en-ca/help/324069/how-to-set-up-an-https-service-in-iis