I am stuck in where I need to download iTunes in order to restore my iPhone as credentials are lost. However, I am using Ubuntu though, I tried downloading iTunes using wine but cannot open it. There can be an issue with drivers.

I never used iTunes, it is for restoring the device as mentioned in the link: https://support.apple.com/en-us/108969.

Any suggestions how to proceed with this, or having a Windows/Mac is a must?