The Anywhere for Retail app supports GTIN barcodes. A Global Trade Identification Number (GTIN) is a 14-digit data structure used to uniquely identify trade items, products, and services at a unit level. To scan items by GTIN codes with a mobile device, you must assign the GTIN codes to items in D365 F&SCM. Please, check the Microsoft documentation on how to do so.
To be able use GTIN barcodes in the Anywhere for retail app, you must allow this in the Anywhere app parameters for Retail for these processes:
Item info
Store transfers
Tag counting
Receipt journal
Inventory adjustment