Google App Script (Exception: Error retrieving image from URL or bad URL)

I'm tryna create a google app script code that will retrieve image files from a folder and insert them into cells in a column.

All sheets within this spreadsheet have the same template, so all getRange() rows and columns are correct.
All images within all folders that I'm trying to retrieve images from have standardised dimensions of ‪1,202 x 720‬ pixels (98KB), are in JPG format, and its names are just Slide1.JPG, Slide2.JPG, etc.

const ss = SpreadsheetApp.getActiveSpreadsheet();
const sheet = ss.getActiveSheet();

function insertImgsFromDriveFolder() {
  Logger.log('sheet name: ' + sheet.getSheetName());
  Logger.log('Drive Folder ID cell: ' + sheet.getRange(1,4).getA1Notation());
  var folderID = sheet.getRange(1,4).getValue();
  Logger.log('Drive Folder ID: ' + folderID);
  var folder = DriveApp.getFolderById(folderID);

  var files = folder.getFiles(); // retrieves Iteration of files, sometimes in reverse order

  // so must get count of no items in folder
  var count = 0;
  while (files.hasNext()) {
    var file = files.next();
    count++;
  }

  // then search for each item by name + display in sheet
  for (let i=1; i <= count; i++) {
    var imgFile = folder.getFilesByName("Slide" + i + ".JPG").next();
    //imgFile.setSharing(DriveApp.Access.ANYONE, DriveApp.Permission.EDIT);
    Logger.log('filename: ' +imgFile);
    img = SpreadsheetApp.newCellImage().setSourceUrl('https://drive.google.com/uc?export=view&id=' + imgFile.getId()).build();
    Logger.log('file: ' +img);
    sheet.getRange(i+4,2).setValue(img);
  }
}

The error message I receive in the Execution log is "Exception: Error retrieving image from URL or bad URL: <URL>" on the sheet.getRange(i+4,2).setValue(img); line.

I am able to view the image by copying that URL from the error in Chrome's Incognito Mode (no google account signed in), so I think the file is publicly-accessible. I am also able to manually insert an image into a cell using that URL using =IMAGE(<URL>). De-commenting imgFile.setSharing(DriveApp.Access.ANYONE, DriveApp.Permission.EDIT); to force it to be public-accessible results in the same error.

I also think that the file size is not an issue as it smaller than the size limit stated in this post.

I also do not want to use insertImage() as I want the images to be inserted into the cells.
I have also tried the solutions provided in here, here and here.

Lmk what I can try to fix this issue! Also, if you also have a solution on how to force the FileIteration to take files in alphabetical/date-created order that would be awesome.

Thanks in advance!

From your comments, I believe your goal is as follows.

• You want to retrieve the image files by the filename like Slide1.JPG, Slide2.JPG, Slide3.JPG, Slide4.JPG, Slide5.JPG,,, in order, and want to put them to the cells "B5:B" using Google Apps Script.
• The format of filename is constant like Slide1.JPG, Slide2.JPG, Slide3.JPG, Slide4.JPG, Slide5.JPG,,,.

Modification points:

• In the current stage the images can be put into multiple cells using setValues.
• In your script, 2 loops are used. I thought that a single loop can be used.
• From your error message Exception: Error retrieving image from URL or bad URL:, in this case, as a workaround, I would like to propose putting the images as the data URL.
• About the sort of files, how about

When these points are reflected in your script, it becomes as follows.

Modified script:

function insertImgsFromDriveFolder() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sheet = ss.getActiveSheet();
  var folderID = sheet.getRange(1, 4).getValue();
  var folder = DriveApp.getFolderById(folderID);
  var files = folder.searchFiles("title contains 'Slide' and mimeType contains 'image' and trashed=false");
  var ar = [];
  while (files.hasNext()) {
    var file = files.next();
    var filename = file.getName();
    var mimeType = file.getMimeType();
    if ((/Slide\d*\.JPG/i).test(filename)) {
      var base64 = Utilities.base64Encode(file.getBlob().getBytes());
      var img = SpreadsheetApp.newCellImage().setSourceUrl(`data:${mimeType};base64,${base64}`).build();
      ar.push({ filename, createdDate: file.getDateCreated(), img });
    } else {
      console.log(filename); // If the file is not your expected file, you can see them in the log.
    }
  }
  if (ar.length == 0) return;
  ar.sort((a, b) => Number(a.filename.match(/Slide(\d*)\.JPG/i)[1]) < Number(b.filename.match(/Slide(\d*)\.JPG/i)[1]) ? -1 : 1);
  sheet.getRange(5, 2, ar.length).setValues(ar.map(({ img }) => [img]));
}

• When this script is run, the images are retrieved and converted to the data URL. And, the data URLs are put into the cells "B5:B" of the active sheet as the images.
• In order to retrieve the files, I used the search query of title contains 'Slide' and mimeType contains 'image' and trashed=false.

Note:

• In this script, it supposes that your folder ID and the image files are valid. Please be careful about this.

References:

• searchFiles(params) of Class Folder

• sort()

• base64Encode(data)