How do I recover iPhone passcode without losing data?

Passcode to login or Password to your Apple Account?

If it is the Passcode, then the phone will need to be wiped to reset the Passcode, but all data will be restored as long as you have been using iCloud to back up your data. Also, any data stored in iCloud will remain after resetting the device.

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

If it is the Password to your Apple Account, then that can be reset without losing your data or having to reset your phone. There are 3 options to reset the Password and it can be by using another Trusted Device logged into your account, a Trusted Phone Number on your account, or using Account Recovery.

If you forgot your Apple Account password - Apple Support

If you forgot your iPhone passcode or your iPhone is disabledApple SupportOfficial Apple Support › en-us

Resetting the passcode requires that the iPhone be erased and set up again. There are no other ways.

You can restore the data on your phone from your current backup, so the phone will look just like it did before you forgot the passcode.

Now.....if you are saying that you don't have a backup of the iPhone......I am afraid that you are going to learn a very painful lesson about the importance of always having a current backup of your phone on iCloud or a computer.

You can’t “recover” the passcode. Either you remember it or you don’t. If you don’t, the only option is to erase the phone and restore from your last backup. There is no way to bypass it.