Please I want to unlock my iPhone 7lus

You might need to be more specific on what do you see on the screen when you try to use the device.

Do you see and activation lock screen, device disabled or do you want to unlock it from a carrier (use different SIM card)?

It's very important as well the way that you "erased the data", did you do it through "Erase all content & setting" from the Settings>General>Reset or did you restore it through iTunes?

Locked in what way? What indicates to you that the device is locked? What message/screen are you seeing that states it is Locked?

GB