Box File Chooser in Angular App

Hello there,

I am new to Box and have been tasked with allowing our clients (who have their own account in Box) to upload files from their Box accounts into our application (along with Google Drive/OneDrive/Dropbox). 

I expected to need only to add a small script to my page, supply a "client id" for my app and an allowed referrer. e.g. Dropbox integration. 

I have been unable to find any examples of this anywhere. 

Can someone point me to a working example. I am running a client-side app in angular. 

Thank you!