@nello_msn_sa If you will use Kakao APIs, app key and developer account will be required because of enabling SDKs and setting up application’s properties.
But a normal user which would like to share a certain page/content don’t need a Kakao account if you use KakaoTalk link API. It will be enough that the user has KakaoTalk app in his phone.
If you need english page, please see the following topic.
https://devtalk.kakao.com/t/you-need-documents-in-english/9426