The spec for this action:
https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2111850
An example of a form using this action:
https://www2.illinois.gov/rev/forms/reg/Documents/reg-1-mr.pdf
this.container.className = "fileAttachmentAnnotation";
    const trigger = document.createElement("div");
    trigger.style.height = this.container.style.height;
    trigger.style.width = this.container.style.width;
    trigger.addEventListener("dblclick", this._download.bind(this));
    if (
      !this.data.hasPopup &&
      (this.data.titleObj?.str || this.data.contentsObj?.str)
    ) {
      this._createPopup(trigger, this.data);
    }
    this.container.appendChild(trigger);
    return this.container;
  }
  /**
   * Download the file attachment associated with this annotation.
   *
   * @private
   * @memberof FileAttachmentAnnotationElement
   */
  _download() {