WeChat.SubscribeMessage.add_template

You're seeing just the function add_template, go back to WeChat.SubscribeMessage module for more information.
Link to this function

add_template(client, tid, kid_list, scene_desc \\ "")

Specs

add_template(WeChat.client(), tid(), kid_list(), scene_desc()) ::
  WeChat.response()

组合模板并添加至帐号下的个人模板库 - 官方文档