You can always change your default connection preference in your profile settings.
If you selected Browser at first and you want to change to Receiver you have to download the Citrix Receiver. Please use this link http://receiver.citrix.com.
MyGDaaS can be accessed from any HTML5 browser. For extended functionality (eg. multiple screens) and best user experience, we recommend installing the Citrix Receiver and selecting Receiver.
Select your avatar at the top right. Choose Profile. The selected connection preference will make sure that every time you launch your desktop, you will connect either via Receiver either via Browser.