Generating barcode for ISBN for print book cover design?

Hello

QR codes aren't the same thing as ISBN barcodes. The Generate QR Code feature in InDesign creates a QR code (usually a square code you scan with a phone) and it can contain text, web links, contact details and so on.

An ISBN barcode is different. It's the standard retail barcode you see on the back of books, made of vertical bars. ISBNs are encoded using the EAN-13 barcode format (typically), sometimes with an extra 5-digit price code on the side (EAN-5) if needed.

So typing an ISBN into the QR Code generator won't produce the correct barcode for book printing.

If you want to make an ISBN barcode, you can:

Use a free online generator, for example:
https://barcode.tec-it.com/en/ISBN13

Or use a dedicated tool or plugin if you want more control inside InDesign - for example:
https://www.barcodeproducer.com/articles/creating-real-barcodes-for-adobe-indesign

To test the barcode, just use any barcode scanner app on your phone or a handheld scanner if you have one. It should read the number exactly as your ISBN.