A WhatsApp session message, built with Unicom360.WhatsApp.Session and sent with
Unicom360.WhatsApp.send_session/3.
to- the recipient's WhatsApp number.type-"text","image","video","document","audio","sticker","interactive","location","contacts"or"reaction".content- the type's own field, in the API's shape (%{"text" => "Hi"},%{"media" => %{"url" => ...}}, ...).from,reply_to,user_reference_id,callback_url- the common optional fields.
The struct is plain data: change a common field with %{message | user_reference_id: "s-1"}.