When performing current measurement for power cord through a new clamp meter, why the measured current is zero constantly?

Clamp the single core when performing current measurement through clamp meter, the clamp meter calculates the current by inducing surrounding magnetic fields. If live and neutral wires are measured together, the directions of magnetic fields of both wires will be offset, so the measured current is zero constantly. Please clamp a live wire by the clamp jaw to perform current measurement.