access previous version of the iphone backup

Hey there dandan128,

Thanks for reaching out to the Apple Support Communities. For the best steps on how to locate previous iPhone backups, check out the steps listed in this link here: Locate backups of your iPhone, iPad, and iPod touch - Apple Support

Find and manage backups stored in iCloud

If you use iCloud Backup, you won't find a list of your backups on iCloud.com. Here's how to find your iCloud backups on your iOS or iPadOS device, Mac, or PC.

On your iPhone, iPad, or iPod touch:

1. Go to Settings > [your name] > iCloud.

2. Tap Manage Account Storage, then tap Backups.

3. Tap a backup to see more details about it, choose which information to back up, or delete the backup.

If wanting to restore information from a previous backup, this would require you to erase all the contents from the device first. For more details, check out this link here: Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Let us know if that's able to help.

Cheers!