How to use the pdf-lib.PDFHexString.fromText function in pdf-lib

function buildPdfObjectsForOutline (layer, context) {
  for (const [i, item] of layer.entries()) {
    const prev = layer[i - 1]
    const next = layer[i + 1]

    const pdfObject = new Map([
      [PDFName.of('Title'), PDFHexString.fromText(item.title)],
      [PDFName.of('Dest'), PDFName.of(item.destination)],
      [PDFName.of('Parent'), item.parentRef]
    ])
    if (prev) {
      pdfObject.set(PDFName.of('Prev'), prev.ref)
    }
    if (next) {
      pdfObject.set(PDFName.of('Next'), next.ref)
    }
    if (item.children.length > 0) {
      pdfObject.set(PDFName.of('First'), item.children[0].ref)
      pdfObject.set(PDFName.of('Last'), item.children[item.children.length - 1].ref)
      pdfObject.set(PDFName.of('Count'), PDFNumber.of(countChildrenOfOutline(item.children)))
    }

    context.assign(item.ref, PDFDict.fromMapWithContext(pdfObject, context))