how do i back up passwords
How do I back up passwords from my old phone
iPhone SE, iOS 13
Question marked as
Assuming you still have the old phone, and it is signed into your AppleID, you can turn on iCloud Keychain (Settings app > AppleID > iCloud > Keychain). Although this is actually a synch process, not a backup.
Also a password manager app/service such as 1password might be worth investing in.