The Instagram Widget needs to access Instagram’s API, which uses tokens to authenticate requests.
How do I get one?
To get an Access Token, you can simply head over this website which allows you to get a token without registering an application in Instagram Developers’ area. Once you log in (note: the website we’re suggesting doesn’t get access to your password), you can simply copy the token it generated and paste it in your widget. Then simply insert your or someone else’s username, a number of the pictures you want to see, and you’re done!