I have a clamp meter for amperage so that should be able to shed some light on the issue.
How do you intend to use it? Not that I've ever opened them, but both the cable that connects the wall socket to the charger and the one that connects the charger to the bike have a sheath that must cover more than a wire, including a hot wire that brings the current to its destination and a neutral that returns it to the source. Because of this, the net current that a clamp meter would measure, with both cables, is zero. One way in which you can still measure the current is to have an extension cord for the wall socket with split wires, but personally I've never seen one and I doubt that they are available. So, if you think that you can do it safely, you can make one by just breaking the sheath of a common extension cord, separate the wires and use the meter only with either the neutral or the hot wire.
EDIT:
Also, there are three orange cables on the inverter of the Gen1 and I guess that:
one is the hot for the battery-inverter connection,
one is the neutral still for the battery-inverter connection,
one is connected to the charging port and I think that it contains two wires.
I imagine that the inverter of the Gen2 doesn't have the third one but still has the other two.
Apparently, during charge, the current passes through the inverter before reaching the battery. I guess that a clamp meter would record the current around either the hot or neutral orange cable, that don't need to be split.
As always, be careful with insulations and don't pull wires with the clamp.