Ionic 4 Zoom Object is not a function issue

I am trying to add zoom SDK in my ionic 4 projects and I am referring the zoom marketing SDK integration document but when I run ionic cordova run browser it is giving me the error object is not a function after the implementation of the zoom plugin.

Ionic Info:-
ionic (Ionic CLI) : 4.0.6 (C:\Users\Uvesh\AppData\Roaming\npm\node_modules\ionic)
Ionic Framework : ionic-angular 3.8.0
@ionic/app-scripts : 3.2.4

cordova (Cordova CLI) : 9.0.0 (cordova-lib@9.0.1)
Cordova Platforms : android 8.1.0, browser 6.0.0

Android SDK Tools : 26.1.1
NodeJS : v13.10.1 (C:\Program Files\nodejs\node.exe)
npm : 6.13.7
OS : Windows 10

ANDROID_HOME : H:\Android\Sdk