HOW TO RESTORE MY IPHONE 8 WITHOUT A MAC

You will need to restore the device using a computer. The process will erase the device. Later you can restore your data from a recent back-up. Instructions here…

If you forgot your iPhone passcode - Apple Support

The computer does not have to be a Mac. Perhaps a friend can help pr you can make an appointment at the nearest Apple Store for assistance.

Apple Store - Find a Store - Apple

You don't need a comouter -> (iOS 15.2 and newer) How to reset your iPhone, iPad or iPod touch if you've forgotten your passcode

How to reset your iPhone, iPad or iPod touch if you've forgotten your passcode – Apple Support (UK)

You can use a WindowsOS computer.

If you don’t have a macOS or Windows OS computer, ask a friend, acquaintance or family to use their computer, or at a public library.

Alternately, visit your local Apple Store or Apple Authorized Service Provider and they should be able to help you out.

You will first have to make an appointment due to the pandemic.

See: Contact Apple for support and service

Contact Apple for support and service - Apple Support