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):

warn(`_getElementsByName - element not allowed: ${id}`);
            continue;
          }
          fields.push({ id, exportValue, domElement });
        }
      }
      return fields;
    }
    
    
    for (const domElement of document.getElementsByName(name)) {
      const { exportValue } = domElement;
      const id = domElement.getAttribute("data-element-id");
      if (id === skipId) {
        continue;
      }
      if (!GetElementsByNameSet.has(domElement)) {
        continue;
      }
      fields.push({ id, exportValue, domElement });
    }
    return fields;
  }
  show() {
    if (this.container) {
      this.container.hidden = false;
    }
    this.popup?.maybeShow();
  }
  hide() {