Further reading: The old Instagram API will be gone early 2020. See: https://developers.facebook.com/blog/post/2018/01/30/instagram-graph-api-updates/
In future, access to Instagram will only be possible through a new Facebook Graph API, and then only to Instagram Business Accounts. See: https://developers.facebook.com/docs/instagram-api
@NickWB: Do you have a Instagram Business Account? Anything feasible to do? See: https://www.freelogoservices.com/blog/2018/02/20/how-to-set-up-an-instagram-account-for-your-business/