Hello Dirizhor,
Were you using iCloud Keychain possibly? If so, you'd need to sign back in to the same iCloud account and enable iCloud Keychain using these steps: Set up iCloud Keychain - Apple Support
In case you ended up having to reset keychain, then there isn't a way to restore these older saved passwords or related verification codes through iCloud or the device. Resetting keychain would erase all saved passwords and websites, essentially making you start over. Learn more below: If iCloud Keychain won't turn on or sync - Apple Support
If you don't see your iCloud Keychain items
There are several possible reasons for why you can't find your iCloud Keychain information.
Did you restore from an iCloud backup and then notice missing iCloud Keychain items?
iCloud Keychain items aren't part of iCloud backup because they already live in the cloud. To see if iCloud Keychain is turned on, in iOS 10.3 or later, tap Settings > [your name] > iCloud > Keychain. For iOS 10.2 or earlier, tap Settings > iCloud > Keychain.
Did you turn off iCloud Keychain on all your devices?
If so, your iCloud Keychain is removed from the cloud. If you chose to delete the keychain items from your devices when you turned off iCloud Keychain, your iCloud Keychain is also removed from those devices. You need to set up iCloud Keychain and add items again.
If you turn off iCloud Keychain on all your devices, and choose to delete your iCloud Keychain locally on all your devices, this also deletes your Keychain data from iCloud servers.
On your Mac, did you use Keychain Access to reset your iCloud Keychain?
If so, macOS deleted your iCloud Keychain items. Try to set up iCloud Keychain again. If you need to reset your Mac Keychain again, temporarily disable iCloud Keychain in iCloud Preferences before you reset your macOS Keychain.
Alternately, you could contact the app developer for further help regaining access to the Instagram account: How to contact an app developer
Hoping this helps out, take care.
