It was announced recently that South Africa was looking to import 1000 MW of electricity from Mozambique - to be generated with Mozambican gas from Cabo Delgado - initially only 100 MW and then later the greater amount.
AmaranthCX is working on what will be the Southern African Power Pool power map's new and improved Southern African Power Pool transmission and distribution grid layer.
From this, one can see that there are two separate electricity grids in Mozambique, linked via Zimbabwe's and South Africa's grids. And it is clear that there is not much infrastructure between the far northern Cabo Delgado and the south - much of it just a low capacity 66 kV line. There is also no gas pipeline infrastructure either.
The only assumption then must be that the gas will be shipped south to Maputo by sea, offloaded and used to generate electricity somewhere in or around Maputo, and then supplied to South Africa using existing grid capacity.