Hello Anas,

So, the only way I make it work was by redo the native app of Barcode.
I had a collegue that created a GS1 nomenclature custom, and had to change the native code of Odoo.
In the demo it works, and with a demo datamatrix it also works, but then with a real one I tried and failed to make it work without some code review.

Thanks Bruno for the comment. However I succeded to make it work without any code change. It seems that Odoo is able to identify GS1 barcode when the code is scanned without the "()" characters. For example, when I scan my Barcode in Excel is displays as follows:
(01)53582910080355(17)210415(10)9S444

Odoo doesn't recognize it and give the error "You are expected to scan one or more products."

But when I remove the brackets from the barcode to read as below
015358291008035517210415109S444
Odoo recognizes it and automatically selects the correct product and add the batch number and expiry date.

So now I only need to figure out how to stop transmitting the () brackets in the scan. an ideas?

I succeeded in configuring Odoo to identify the barcode including the brackets "()".
In developer mode under GS1 nomenclature, I added the () in the expression and it works like a charm now. (This is in v16 so I think same would work in v15)

The original expression in the GS1 nomenclature was
(01)(\d{14})
I changed it to
(\(01\))(\d{14})

Did the same for all the application identifiers:
(\(17\))(\d{6})
(\(10\))([!"%-/0-9:-?A-Z_a-z]{0,20})
(\(21\))([!"%-/0-9:-?A-Z_a-z]{0,20})

You have to modify Odoo.
My project was in Pharma, so GTIN + Expiration date + Lot
Check the V16 I think is fixed there.
We end up making a module to teach Odoo how to read a datamatrix.
Also check OCA, I think they have a external solution for this.

Ho Bruno,
Thank you for your reply!
Yes, in v16 Fabien did a demo using the system... so it should be working. We reported back to Odoo and will now wait for their answer.
Thank you again!