I'm implementing webhook subscription to receive notifications about new comments on Instagram media (so, the solution assumes server side environment). Webhook payload contains a comment ID. Fetching a comment node via Facebbok API Graph call I can get author's username. From this point I need to get author's profile picture.
Currently I can use Business Discovery API to get information about user by username like this
GET graph.facebook.com/%PAGEID%
?fields=business_discovery.username(%USERNAME%){...fields...}
But this method is working only for Instagram Business accounts.
Recently, this task can be accomplished with https://www.instagram.com/%USERNAME%/?__a=1 call, but now this request requires authorization.
You cannot get the user profile picture by using the username, because facebook denies querying users by their username:
(#803) Cannot query users by their username
Even if, indeed, getting the facebook picture of a user does not require an access token or any permissions.
You need to get the userid (10000xxxxxxxxxx), and then you'd be able to:
GET https://graph.facebook.com/v3.2/{userid}/picture