Custom API is represented as an object composed of asynchronous methods that you set on your Appmixer SDK instance using the api option:
var myCustomApi = {/* the key must match an existing API method */myCustomApiMethod(/* arguments of the original method */) {returnnewPromise((resolve) => {resolve(myCustomResponse); }); }}/* Use a custom API on the entire SDK instance */var appmixer =newAppmixer({ api: myCustomApi });/* Use a custom API on a particular SDK UI widget */var designer =newappmixer.ui.Designer({ api: myCustomApi });