EAN 13 check digit

[aminemarckader]

Good morning, please I would like to note that I can't find a way to generate a check digit to add it to the database and the label.
I tried 123456789012 as a barcode and when displaying the label I only get the 12 digits without the check digit included.
Please, can you add a method to get it or include it directly in the label.
THANKS IN ADVANCE.