Open URL in InAppBrowser via _blank not working

I use the following code hosted on github to open the dropbox auth page via InAppBrowser (_blank), but it always opens in an external browser. Any idea why?

https://github.com/tinydream12/Ionic2-dropbox

Could be various reasons, I’m not checking your app. It could be that dropbox forces it to, could be that you did not wildcard the allowed url’s in cordova etc.

It’s not my app. I found the code on github. Dropbox does not force the the external browser to open, I checked with other URLs aswell. I’m coding another app, which work almost the same as the dropbox app. I wondered why the InAppBrowser was not openen in an actual in-app-browser, but instead it opens an external browser. So there must be another problem than the code.