how can i restore my backup

On a Mac (macOS 10.15 or later): In the Finder sidebar, select your iPhone, click Trust, then click “Restore from this backup.” On a Mac (macOS 10.14 or earlier) or a Windows PC: Open the iTunes app, click the button resembling an iPhone near the top left of the iTunes window, click Summary, then click Restore Backup.

By using these instuctions:--> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support