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):

element.addEventListener("resetform", event => {
        const defaultValue = this.data.defaultFieldValue ?? "";
        element.value = elementData.userValue = defaultValue;
        elementData.formattedValue = null;
      });
      let blurListener = event => {
        const { formattedValue } = elementData;
        if (formattedValue !== null && formattedValue !== undefined) {
          event.target.value = formattedValue;
        }
        
        event.target.scrollLeft = 0;
      };
      if (this.enableScripting && this.hasJSActions) {
        element.addEventListener("focus", event => {
          if (elementData.focused) {
            return;
          }
          const { target } = event;
          if (elementData.userValue) {
            target.value = elementData.userValue;
          }
          elementData.lastCommittedValue = target.value;
          elementData.commitKey = 1;
          elementData.focused = true;
        });
        element.addEventListener("updatefromsandbox", jsEvent => {
          this.showElementAndHideCanvas(jsEvent.target);
          const actions = {
            value(event) {