Templating techniques for Web-pages
Cards and Kanban don't require to connect additional Endpoint. custom HTML view operates with the fields of an object directly.
If you want to use data or global variables in your component, you should turn on that feature in the component settings:

The same way, that we apply in scenarios
{{GlobalVar.myGlobalVar}}
{{id}}
{{role}}
{{firstName}}
{{HttpRequest.paramName}}
If you connect API-endpoint, you can deal with objects it provides.
{{#contentHead}}
{{firstName}} {{lastName}}
Project {{project_id.title}} // here project_id is a link
{{/contentHead}}
// the result may look like
Steve Jobs
Project Apple
{{#content}}
- {{firstName}} {{lastName}} launched {{project_id.title}}
{{/content}}
// the result may look like (for 2 objects, provided by API-endpoint)
- Steve Jobs launched Apple
- Bill Gates launched Microsoft
The mechanism is similar to the one used for scenarios
{{#arraylink_field}}
- {{title}} {{city}}
{{/arraylink_field}}
// the result may look like (for 2 objects in the arrayLink field)
- Apple Cupertino
- Microsoft Seattle
Similar to the Templating in scenarios
/ shows if is_vip == true
{{#is_vip}}vip{{/is_vip}}
// shows if is_vip == false
{{^is_vip}}not vip{{/is_vip}}
You may apply complex HTML for building beautiful custom pages.