Here is an example project showing how to load and use the SDK.
The only way I got it to work was by using a script tag with the url of the SDK. When the script is loaded and executed it creates the global variable Realm which you can use to do whatever it is supposed to do.
The project uses two scripts. The first scriptLoad.js defines the function that loads a script tag with a provided URL. It has it's Purpose property set to (not set). This means C3 doesn't do anything with it that you don't explicitly tell it to.
The other script, importForEvents.js has it's Purpose property set to Import for events. This one just imports the first script so the function to load a script tag is available in event sheets.
Since the loading is asynchronous, the load function returns a promise that will resolve to true or false depending on wether loading was successfull or not. So make sure to always check for that before using the global Realm property.
The example only prints to console, so press F12 to bring up dev tools for the preview window to see if it is working or not.