Instagram is not available in the AppStore
How to get instagram
iPhone 6s
Question marked as
Depending where you live and to which country your Apple ID has been registered, not all apps are available.
If other users in your country have successfully installed this app, did you check for any restrictions that might be set up in the settings for Screen Time on your device?
You will have to upgrade your iPhone to at least iOS 13.4, to be able to install Instagram