If the 'People tab' does not show up in your Apple Developer dashboard, you most likely need to update your Entity type to 'Organization'.

To accomplish this, have your DUNS number ready and visit https://developer.apple.com/contact/#!/topic/select . Select Membership and Account then Program Enrollment. Let Apple Support know you'd like to change your account's entity type to "Organization" and they can tell you what else is necessary to complete the change.