I think this is the most inconvenient detail on Instagram. But private profiles can’t be viewed without the owner’s permission, even if you’re registered with the app. I remember once losing my account password, but I didn’t want to create a completely new profile. And you know, until I recovered my old profile, blinkviewer.com helped me view other accounts. I remember finding it in some public groups. Both the app and the viewer really lived up to their reviews and did the job just fine.