To allow calls with methods HTTP and HTTPS to be served by Mashery the configuration "Customize your Public Endpoint Address" should be set to HTTP with the proper hostname and URI. The following screenshot provides the configuration.
The following calls can served using this configuration.
curl -v -i "https://api.mashery.com/datacenter/test/?api_key=<api_key>"
curl -v -i "http://api.mashery.com/datacenter/test/?api_key=<api_key>"
To get the HTTPS call working the public hostname should have a valid SSL certificate. Article "000035175: Enabling SSL for client facing hostnames" provides details on the process of how to get SSL certificate uploaded for a client facing hostname hosted by Mashery.