How to delete text messages without turning on your mobile phone?

No, all mobile phones are the same. You can't use the function in your mobile phone without unlocking it. Otherwise, you need a password to do something. Anyone can access the content of the mobile phone. No matter what brand of mobile phone it is, you can't delete messages as long as it is unlocked. Only by unlocking the phone can you see the short message, and then delete it. No brand of mobile phone can enter the SMS page until the lock screen is unlocked. You can try if you don't believe me.

If the phone is not unlocked, it should be impossible to delete the SMS. It must be unlocked, otherwise the lock is meaningless.