Authorizing a Third Party Platform - Wechat Mini Program

Hi All, I am building a wechat mini program that authorizes a third party say for example an email service provider. I have went through the below document for authorizing the third party https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&lang=en_US

But am not sure where to configure this third party platform and also how to get the third party app id. It would be great if someone help me on this.If possible with some sample mini program which authorizes a third party platform.

Thanks in Advance !!!