Similar question about Instagram has been asked recently here:
You need to obtain the Client ID and Client Secret from Instagram (belonging to Facebook) as per their documentation. The latest info about their process should be documented there, and there were quite a few changes around Instagram in the near past, since Facebook doesn’t any longer recommend Instagram to be used as IdP but recommends Facebook, therefore, it’s best to consult the Instagram documentation.
Auth0 does not support Instagram social connection out of the box anymore, therefore you’d need to use the custom social provider extension, as mentioned in the linked thread above.
Also see the deprecation note: