WeChat.Storage.Client.fetch_ticket

You're seeing just the callback fetch_ticket, go back to WeChat.Storage.Client module for more information.

fetch_ticket(appid, type, args)

Specs

fetch_ticket(appid :: String.t(), type :: String.t(), args :: term()) ::
  {:ok,
   %WeChat.Ticket{
     expires_in: term(),
     timestamp: term(),
     type: term(),
     value: term()
   }}
  | {:error,
     %WeChat.Error{
       __exception__: term(),
       errcode: term(),
       http_status: term(),
       message: term(),
       reason: term()
     }}

Fetch ticket of WeChat common application, the option of type parameter is "wx_card" or "jsapi"(refer WeChat Official document).