WeChat.sign_card

You're seeing just the function sign_card, go back to WeChat module for more information.

sign_card(list)

sign_card(list :: [String.t()]) :: WeChat.CardSignature.t()

To initialize WeChat Card functions in JSSDK, use wxcard_ticket and card_id to generate a signature for this scenario, see official document.

sign_card(wxcard_ticket :: String.t(), card_id :: String.t()) ::
  WeChat.CardSignature.t()

sign_card(
  wxcard_ticket :: String.t(),
  card_id :: String.t(),
  openid :: String.t()
) :: WeChat.CardSignature.t()