Underground cable outside for electric courtyard gate: 3x1.5mm² or 5x1.5mm²?

Or does the motor need three-phase current?

That was my first assumption, that one phase is not enough. But others say that one is sufficient. Maybe it depends on the type of gate and motor.

Because if it’s about control lines, I would have expected 3x1.5mm and the control line separately, but not included in the cable for low voltage. But well, only the supplier and manufacturer know that.