WeChat.CustomMessage.send_mini_program_page

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

send_mini_program_page(client, openid, map)

Specs

send_mini_program_page(WeChat.client(), WeChat.openid(), map()) ::
  WeChat.response()

客服消息接口 - 发送小程序卡片(要求小程序与公众号已关联) - 官方文档

Example

WeChat.CustomMessage.send_mini_program_page(client, openid, {
  title:    "title",
  appid:    "appid",
  pagepath: "pagepath",
  thumb_media_id: "thumb_media_id"
})