Exporter/Export Agent Name on Export Declarations when Procuring Equipment for Overseas Construction Sites

I am in charge of procuring construction equipment for overseas construction sites at a construction company, and I have an inquiry regarding the designation of the Exporter/Export Agent on export declarations. The current situation is as follows: 1) A purchase contract is signed between our company and a domestic equipment supplier. 2) A Purchase Confirmation (구매확인서) is issued to apply the zero-rated VAT rate. 3) The delivery term in the purchase contract is FOB domestic port, and the export declaration is performed by a customs broker designated by the supplier. 4) The export declaration is filed with our company as the Exporter/Export Agent and the supplier as the Manufacturer. The problems are: - Since the supplier designates the customs broker, our company cannot control the correction or amendment of the export declaration. - Our company faces sanctions due to reporting errors made by the customs broker. - Because our company is designated as the Exporter, the responsibility for strategic item determination and export licensing falls on us, but we face operational inefficiencies due to a lack of accurate information regarding the equipment. Questions: 1) When a purchase contract is signed with a domestic supplier for the purpose of installation at an overseas construction site and a Purchase Confirmation is issued, must our company necessarily be designated as the Exporter/Export Agent on the export declaration? 2) If a Purchase Confirmation is issued, is there any way to designate the supplier as the Exporter/Export Agent on the export declaration? 3) I would appreciate it if you could provide the names of the laws and the specific article numbers that regulate this.