Inquiry regarding integrated LC negotiation for partial shipments and how to prepare the Commercial Invoice

From an exporter's perspective, I am conducting an LC negotiation transaction that allows partial shipments under FOB terms, and I plan to make partial shipments from Spain and Korea respectively. When proceeding with the negotiation, I am wondering if I can perform a single integrated negotiation based on the latest shipment date among the two shipments. Additionally, I have a question regarding how to prepare the Commercial Invoice. I plan to prepare the Packing List, B/L, and Certificate of Origin for each respective shipment from Spain and Korea, but since the Commercial Invoice must state the total amount, I am in a situation where I cannot separate the amounts by country. In this case, how should I prepare it, and is it acceptable to state the LC negotiation amount (the integrated total)?