Before start, you need to make sure that the iCloud you logged on iPhone 8 is the same with the iCloud backup account. Then follow the steps below to restore iCloud backup to iPhone 8 directly: Step 1. Firstly you need to make sure that you have an iCloud backup to restore from. Go to Settings > iCloud > Storage > Manage Storage > tap a device from the backup list. Step 2. Then go to Settings > General > Reset > Erase all Content and Settings. Here you need to type your iPhone passcode. Step 3. Tap Restore from iCloud backup and sign in your iCloud account. Then choose an iCloud backup from a list and wait for the process to complete. How to Restore iCloud Backup to iPhone 8 Directly
How to Restore iCloud Backup to iPhone 8 Directly