Follow these below-mentioned steps to prevent the iPhone from automatically suggesting/generating passwords: 1. Go to your iPhone Settings. 2. After that Go to Passwords. 3. Click on AutoFill Passwords. 4. Turn off / Disable the Autofill Passwords. 5. After that, your auto-filling passwords will get diable and it will no longer suggest any password. Within a few easy steps, you will be able to do this.