In order to connect an ESRI layer to your domain, you need to have a secure HTTPS url for the layer.
Why do I need this? HTTPS is the secure version of HTTP. In fact, the 'S' at the end of HTTPS stands for 'Secure'. Which means all communications between your browser and the website are encrypted!
This format is an industry standard used to establish an encrypted link between a web server and a web client. HTTPS ensures a secure network communication by identifying and authenticating the server as well as maintaining the privacy and integrity of all transmitted data.
For information on how to configure your layer links to the HTTPS format, please follow this link.
For instructions on connecting an ESRI layer, please follow this link.
Note: All Socrata domains fall under this HTTPS format as well, to ensure encryption and security of your data.