Under SOLAS Chapter VI Regulation 2, the shipper must give the carrier a verified gross mass (VGM) for each packed container, obtained by weighing or by a calculation method the authorities allow.
Cargo Optix adds the weights you entered to pallet weight and published container tare, and shows the working. That is a useful cross-check while planning.
It does not verify weights, weigh anything, or sign anything. The verification and the signed declaration remain the shipper's responsibility.
Gross mass figures are planning arithmetic, not a verified VGM declaration. See the Terms of Service.