This Extension function is used to generate check digits. The last digit of some barcodes is a computer check digit which makes sure the barcode is correctly composed.
Supported types (gs1): SSCC, GTIN-8, GTIN-12, GTIN-13, GTIN-14, GSIN
Read more about manually calculating a check digit [here.](https://www.gs1.org/services/how-calculate-check-digit-manually)