When asked, sign in with your Apple ID to restore your apps and purchases. If you've purchased iTunes or App Store content using multiple Apple IDs, you'll be asked to sign in to each. If you can't remember your password, you can tap Skip this Step and sign in later. You won't be able to use the apps until you've signed in with your Apple ID.
Stay connected to Wi-Fi and wait for a progress bar to appear and finish loading. Depending on the size of the backup and the network speed, the progress bar might need a few minutes to an hour to complete. If you disconnect from Wi-Fi too soon, the progress will pause until you reconnect.
Now you can finish setup and enjoy your device. Content like your apps, photos, music and other information will continue to restore in the background for the next several hours or days, depending on the amount of information there is. Try to connect often to Wi-Fi and power to let the process complete.
Restore your device from a backup on your computer
On a Mac with macOS Catalina or later, open the Finder. On a Mac with macOS Mojave or earlier, or on a PC, open iTunes.
Connect your device to your computer with a USB cable. If a message appears asking for your device passcode or to Trust This Computer, follow the onscreen steps. Get help if you've forgotten your passcode.