async function updatePdfFields(pdfBytes, dataSource) {
  // Load the PDF document
  const pdfDoc = await PDFDocument.load(pdfBytes);
  const form = pdfDoc.getForm();

  // Loop over each record in the Wappler data source
  dataSource.forEach((record) => {
    // Loop over each key-value pair in the record
    Object.entries(record).forEach(([fieldName, fieldValue]) => {
      // Find the form field in the PDF by name
      const formField = form.getTextField(fieldName);

      // If the field exists in the PDF, update it with the value
      if (formField) {
        formField.setText(String(fieldValue));
      }
    });
  });

  // Serialize the PDF back to bytes and return
  const updatedPdfBytes = await pdfDoc.save();
  return updatedPdfBytes;
}

// Usage Example
async function main() {
  // Load your PDF as bytes (e.g., using fetch)
  const pdfBytes = await fetch("path/to/your.pdf").then((res) =>
    res.arrayBuffer()
  );

  // Sample data source from Wappler
  const dataSource = [
    { fieldName1: "Value1", fieldName2: "Value2" },
    { fieldName1: "AnotherValue1", fieldName2: "AnotherValue2" },
  ];

  // Call the function to update the PDF fields
  const updatedPdfBytes = await updatePdfFields(pdfBytes, dataSource);

  // Do something with the updated PDF, e.g., download it or display it
}