Using EAN/GTIN or Customer Product number with API (S4/Hana)

Hi Experts,

We are currently implementing SAP S4/Hana MTE. What is the best way to create a Sales Order via API (SAP_COM_0288) using the GTIN/EAN or Customer code?

Our EDI customers may send the EAN/GTIN or their own product code. With the API I do not see any way to use anything else but the SAP material number.

Thank you for you time and effort in answering the question

Regards