If identification isn’t enough, you can set the iPhone to block notifications for any number not in your personal network.

If you go on your Instagram app, go to your “Settings and Activity” page, then select Accounts Center. From there, tap “Password and security” and scroll down to “Security checks.” Tap “Recent emails” ...

In your Instagram account settings (go to your account settings, then click "Accounts Center," then "Password and security," ...

In the Settings app, go to Accessibility > Touch > Back Tap and choose one of two options: double tap or triple tap. You should see a list of actions you can run by tapping the back of your iPhone, ...