You want to install smappee but you have an installation with two electricity meter or a separate heat pump?
The solution would be to use the a Y cable to make the connection between the two counters and the input of Smappee. This cable allows to add up the value of 2 currents from the same phase provided that the 2 clamps have the same direction.
This means the two clamps need to be mounted on the same Phase.
The cable and separate clamps can be ordered here.
For a 3 phase installation there is a set available
which contains 3 current clamps and 3 Y cables.