Activation lock is a security protocol that can't be bypassed. Only the person it is locked to can unlock it.
If you bought this from someone and it came locked, try to get your money back, you will never be able to use the phone.
If your phone is Activation Locked - How to remove Activation Lock -
How to remove Activation Lock - Apple Support
The All Too Common SAD Reality of Buying a Used iPad/iPhone.
The All Too Common SAD Reality of Buying … - Apple Community