Javascript SDK to authorize user and get access token

If you're using the official Dropbox API v2 JavaScript to integrate with Dropbox in a JavaScript app, you should use the supplied 'getAuthenticationUrl' method to build your authorization URL, which will contain whatever redirect URI value you supply. There's a working auth example included with the SDK here. (Instructions for running the examples can be found here.)

On this line, you call the getAuthenticationUrl method, supplying what you want your redirect URI to be. It gives back the full /oauth2/authorize URL, which is where you should send the user. In the example it does so by giving them a link set to that URL so they can click on it. I expect you can alternatively just pass it to window.open though. That would look like:

window.open(dbx.getAuthenticationUrl(redirectUri));

Once the user authorizes the app, Dropbox will redirect them to the specified redirect URI. In the example, the access token is retrieved from the URL fragment here.