Since Instagram has changed their API policies, here is how it should work from now on:
– Instagram keys must be created within your Instagram account first.  Click here to see how to do that.

Go in settings

Then click on Instagram

Capture d’écran 2016-07-15 à 17.10.25

Then fill your API keys :

Capture d’écran 2016-07-15 à 17.10.41