Reading from the source code:

https://github.com/mozilla/pdf.js/blob/57d196e3497e77c81c19f852715ce79d9fb91492/src/display/annotation_layer.js#L2846

it appears to me it was not an intention to mark downloadManager as a required parameter in AnnotationLayerParameters:

https://github.com/mozilla/pdf.js/blob/57d196e3497e77c81c19f852715ce79d9fb91492/src/display/annotation_layer.js#L63

and AnnotationLayerBuilderOptions:

https://github.com/mozilla/pdf.js/blob/57d196e3497e77c81c19f852715ce79d9fb91492/web/annotation_layer_builder.js#L40

and it should be optional, similarly to accessibilityManager for example:

https://github.com/mozilla/pdf.js/blob/57d196e3497e77c81c19f852715ce79d9fb91492/web/text_layer_builder.js#L30

**Configuration:**
- PDF.js version: 2.11.174
- Is a browser extension: no

**What is the expected behavior? (add screenshot)**

`downloadManager` to be optional

**What went wrong? (add screenshot)**

`downloadManager` marked as required

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

const y = data.rect[3] - coordinate.y;
      points.push(x + "," + y);
    }
    points = points.join(" ");
    const polyline = (this.#polyline = this.svgFactory.createElement(
      this.svgElementName
    ));
    polyline.setAttribute("points", points);
    
    
    polyline.setAttribute("stroke-width", data.borderStyle.width || 1);
    polyline.setAttribute("stroke", "transparent");
    polyline.setAttribute("fill", "transparent");
    svg.append(polyline);
    this.container.append(svg);
    
    
    if (!data.popupRef && this.hasPopupData) {
      this._createPopup();
    }
    return this.container;
  }
  getElementsToTriggerPopup() {
    return this.#polyline;
  }
  addHighlightArea() {
    this.container.classList.add("highlightArea");
  }
}
class PolygonAnnotationElement extends PolylineAnnotationElement {