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.
let type = "button";
    let exportValues;
    if (this.data.checkBox) {
      type = "checkbox";
      exportValues = this.data.exportValue;
    } else if (this.data.radioButton) {
      type = "radiobutton";
      exportValues = this.data.buttonValue;
    }
    return {
      id: this.data.id,
      value: this.data.fieldValue || null,
      defaultValue: this.data.defaultFieldValue,
      exportValues,
      editable: !this.data.readOnly,
      name: this.data.fieldName,
      rect: this.data.rect,
      hidden: this.data.hidden,
      actions: this.data.actions,
      type,
    };
  }
  get fallbackFontDict() {