How can I unlock my phone when it’s deactivated

Did you mean that your iPhone has been disabled? If your iPhone has been disabled, then You will need to reset the passcode on the iPhone. You will need a computer to complete this task. You can reset your passcode by following the instructions in this article by Apple ➔ How to reset your passcode on a disabled iPhone. All your data on your iPhone will be wiped clean in the process.

If you have a backup created then you can ➔ Restore Your iPhone from that backup file. If you do not have a backup file created then you will lose all your data on the iPhone.

 If Photos, Messages and Contacts are synced to iCloud then you will be able to retrieve them after setting up iCloud on your iPhone after you reset the passcode and sign into iCloud.

Axel F.