Function to Combine 2 PDFs getting timeout error

Here is my function that I'm using to combine two PDFs into one (this is happening within a larger forEach loop but I didn't include it because I don't want to overcomplicate my question).

I have noted all the console log outputs, which seem to indicate the PDF files are valid and they load successfully. However, the end result of the function is to create a new file called "combined.pdf" and this is not happening. I am getting this error after I run my function: "ReferenceError: setTimeout is not defined"

    // ****** FUNCTION 1 ******
async function loadPDF(pdfBytes) {
try {
const loadedPdf = await PDFLib.PDFDocument.load(pdfBytes);
console.log(`PDF loaded successfully`);
return loadedPdf;
} catch (error) {
console.log(`Error loading PDF:`, error);
return null;
}
}
// ****** MAIN FUNCTION ******
async function combinePDFsIntoOne () {
const cdnjs = 'https://cdn.jsdelivr.net/npm/pdf-lib@1.16.0/dist/pdf-lib.min.js';
eval(UrlFetchApp.fetch(cdnjs).getContentText());
const pdfFile1 = pdf;
const pdfFile2 = pdfP2FileName;
console.log(typeof pdfFile1) //object
console.log(pdfFile1)
/*
{ toString: [Function],
getName: [Function],
getBytes: [Function],
setName: [Function],
getContentType: [Function],
setContentType: [Function],
setBytes: [Function],
getDataAsString: [Function],
setDataFromString: [Function],
isGoogleType: [Function],
getAllBlobs: [Function],
setContentTypeFromExtension: [Function],
copyBlob: [Function],
getAs: [Function] }
*/
console.log(typeof pdfFile2) //object
console.log(pdfFile2)
/*
{ toString: [Function],
getName: [Function],
getBytes: [Function],
setName: [Function],
getContentType: [Function],
setContentType: [Function],
setBytes: [Function],
getDataAsString: [Function],
setDataFromString: [Function],
isGoogleType: [Function],
getAllBlobs: [Function],
setContentTypeFromExtension: [Function],
copyBlob: [Function],
getAs: [Function] }
*/
// Read files as "Binary Strings"
const pdfBytes1 = new Uint8Array(pdfFile1.getBytes()); 
const pdfBytes2 = new Uint8Array(pdfFile2.getBytes()); 
// Create new pdf
const pdfDoc = await PDFLib.PDFDocument.create();
// // Load the first and second PDFs
// const firstPDF = await PDFLib.PDFDocument.load(pdfBytes1);
// const secondPDF = await PDFLib.PDFDocument.load(pdfBytes2);
// Try loading the first PDF
const firstPDF = await loadPDF(pdfBytes1); // PDF loaded successfully
console.log(typeof firstPDF);
if (!firstPDF) {
console.log(`Error loading first PDF ${typeof firstPDF}`);
}
// Try loading the second PDF
const secondPDF = await loadPDF(pdfBytes2); // PDF loaded successfully
if (!secondPDF) {
console.log(`Error loading second PDF ${typeof secondPDF}`);
}
// Get pages to import
const firstPDFPages = await pdfDoc.copyPages(firstPDF, firstPDF.getPageIndices());
const secondPDFPages = await pdfDoc.copyPages(secondPDF, secondPDF.getPageIndices());
// Add pages to the PDF
firstPDFPages.forEach((page) => pdfDoc.addPage(page));
secondPDFPages.forEach((page) => pdfDoc.addPage(page));
const pdfBytes = await pdfDoc.save();
const newBlob = Utilities.newBlob(Array.from(pdfBytes), 'application/pdf');
newBlob.setName('combined.pdf');
holdingFolder.createFile(newBlob);
};
try {
await combinePDFsIntoOne ();
}
catch(err) {
console.log(`Error is: ${err}`) // Error is: ReferenceError: setTimeout is not defined
}

Wow, I found the bug! All I had to do was define this variable:

const setTimeout = function (f, t) {
Utilities.sleep(t);
return f();
}

Thanks again to Tanaike for being such a great resource for Google Apps Script!