Screenshot of the area I only want the snapshot getting from the html2canvas to be the center part (approximately the area between orange lines) of this blue area. What parameters should I set for the method?

My current implementation:

    let doc = document.getElementById("texera-workflow-editor") || document.body;
    html2canvas(doc, {
      allowTaint: true,
      useCORS: true,
      backgroundColor: "rgba(0,0,0,0)",
    }).then(canvas => {
     ...)}