TypeError: client.on is not a function

Hi Team,

I have loaded Zendesk SDK using https://static.zdassets.com/zendesk_app_framework_sdk/2.0/zaf_sdk.min.js and after load ZAFClient object is returned. However init method does not return client object instead returns false.

Code Snippet as follows:

const client = window.ZAFClient.init();

client.on('voice.dialout', function appRegistered(e: any) {
      console.log("test");
    });

Please suggest what should be done to get proper client object.