How to post an already uploaded photo?

Question

Classmates

There is the same photo for everyone, which is already uploaded in the group, how to attach it to each message?

FAPI.UI.postMediatopic({
              "media":[
                  {
                      "type": "text",
                      "text": "Test"
                  },
                    {
                "type": "photo",
                "list": 
                [
                  { "id": ??? }
                ]
              }
              ]
          }, false);