Activation lock

Hi, so guys I'm a developer, but Ia friend had an iphone given from his uncle and when is trying to unlock it , the phone was lock and his uncle dont know anyting because he buy it second hand . So just be cool with me I'm not a youtuber who will post your answer or anything , just tell me if

1) Cant you really do something with it ? FOR ME!

2)Does the CFW method work on ios 11? Sincerely !

Please guys the iphone 7 plus is about 400 dollars I cant just put it in trash , I know that you can understand, We're all humans after all "you understand me and I you!".

Just tell me what to do!