POST image blob to Facebook using Graph API

Question

This is a very popular question and contains overwhelming zero answers on the Internet.

I have a canvas translated into blob that I want to post to Facebook.

How to achieve this, briefly?

Here is what I have developed so far:

    var myCanvas = document.getElementById("myCanvas")

    function shareOnFacebook() {

        myCanvas.toBlob(function(blob) {
          var form = new FormData();
          form.append('newFlagPic', blob, '.png');
          console.log(form)
          FB.api(
              "/me/photos",
              "POST",
              {
                  "source": form
              },
              function (response) {
                if (response && !response.error) {
                  console.log("Success bud")
                }
              }
          );             
        });
    };

I find it absolutely insane that fb does not provide sample code for this, as this is clearly such a commonly used use case. I read various answers in the last 5 hours, and not one of them addresses this fb method.