Dear @m.ibrahim
Thanks for reaching out,
Please find the announcement Introduce new format validation for “Other Buyer ID (BT-46)” and “Other Seller ID (BT-29)” - Announcements - Fatoora Developer Community
You need to check also the buyer not lust the seller.
If you require any additional clarification, please do not hesitate to reach out.
Thanks,
Ibrahem Daoud.