Find Someone Email From Facebook

I am wondering how I can find someone email I got Facebook and Instagram of target but I don't know the email address of the target. I read TheHarvester how to but I don't understand how to get a email of specific person from that. Also I tried to get it with "forget password" but it show like ' blabla@w***.com ' and i don't know the email provider starts with w (also target not that type of has its own email and website). Please help.