In file https://github.com/mozilla/pdf.js/files/5249872/product1.pdf, the fifth text widget has a default appearance using font F1 and this one is neither in DR nor in AcroForm but in AP::N::Resources.
constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.FREETEXT;
  }
}
class LineAnnotation extends MarkupAnnotation {
  constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.LINE;
    this.data.lineCoordinates = Util.normalizeRect(
      parameters.dict.getArray("L")
    );
  }
}
class SquareAnnotation extends MarkupAnnotation {
  constructor(parameters) {
    super(parameters);
    this.data.annotationType = AnnotationType.SQUARE;
  }
}
class CircleAnnotation extends MarkupAnnotation {