Have you tried using the scanning app on your phone to scan other barcodes (like maybe one from a candy bar)?
If the phone app will successfully scan the barcode of a commercial product but fails to scan your generated code, then the problem is NOT in the program or the scan app.
Barcodes are tricky things to produce. The distance between the bars and the width of the black bars must be within some very tight tolerances. Most online barcode generators create a picture file like a jpeg, png, or tiff. Once you then resize that picture you have added distortion to the generated code and it may not be readable by barcode scanners (or smartphones).
If you can, try downloading one of the free barcode fonts available for MS Word and use it to generate a barcode. By using a font to make the barcode you have the benefit of being able to accurately scale the font properly during the creation of the document.
You might then be able to generate your code in the correct size and save it as the picture file later without having to resize it.
All of this is most complicating the generating of barcodes because most of the generators create the picture files and not real barcodes.
The BEST way to generate barcodes is with a barcode printer. The fonts are built into the printer and are scalable to almost any size imaginable.
Two others here on the form have already worked out a solution. One looks like a custom app and the other is just using the ability to customize print formats in v12.
Hope this helps explain the pitfalls of trying to use barcode picture files.
BKM