We could use:
https://github.com/mozilla/pdf.js/blob/c3d08580627471432a6ad0b2fdb948df64126afa/src/display/api.js#L929

and look at bit 4.

The following pdf:
https://orimi.com/pdf-test.pdf
is not editable in neither Acrobat nor Edge nor Foxit and nor Okular.
if (!this._pageLabels) {
      return null;
    }
    const i = this._pageLabels.indexOf(label);
    if (i < 0) {
      return null;
    }
    return i + 1;
  }
  /**
   * @typedef {Object} ScrollPageIntoViewParameters
   * @property {number} pageNumber - The page number.
   * @property {Array} [destArray] - The original PDF destination array, in the
   *   format: <page-ref> </XYZ|/FitXXX> <args..>
   * @property {boolean} [allowNegativeOffset] - Allow negative page offsets.
   *   The default value is `false`.
   * @property {boolean} [ignoreDestinationZoom] - Ignore the zoom argument in
   *   the destination array. The default value is `false`.
   */
  /**
   * Scrolls page into view.
   * @param {ScrollPageIntoViewParameters} params
   */
  scrollPageIntoView({
    pageNumber,
    destArray = null,
    allowNegativeOffset = false,
    ignoreDestinationZoom = false,