Safari and passwords

If you want to view the passwords stored in iCloud Keychain

On your iPhone, iPad, or iPod touch with iOS 12 or later:

1. Tap Settings > Passwords & Accounts > Website & App Passwords.
2. Use Face ID or Touch ID when you're prompted.
3. Tap a website to view your password.

On your iPhone, iPad, or iPod touch with iOS 11:

1. Tap Settings > Accounts & Passwords > App & Website Passwords.
2. Use Face ID or Touch ID when you're prompted.
3. Tap a website to view your password.

On your iPhone, iPad, or iPod touch with iOS 10.3 or earlier:

1. Tap Settings > Safari > Passwords.
2. Use Touch ID or enter your device passcode.
3. Tap a website to view your password.

On your Mac with OS X Mavericks 10.9 or later:

1. Choose Safari > Preferences, then click Passwords.
2. Select a website to view your password.
3. Select Show passwords for selected websites at the bottom of the window.
4. Enter your Mac password.

Get help with iCloud Keychain - Apple Support

https://support.apple.com/en-us/HT203783

If you weren't syncing Safari with iCloud, do you have a backup you can restore from?

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you.