The CCL feature in the ATmega4809 can be used to provide complementary outputs of a Timer/Counter output. LUT0 or LUT3 outputs to A5 and LUT2 outputs to A0. LUT inputs can come from any of the Timer/Counter outputs and by setting the Truth Table registers you can have one LUT invert and the other non-inverting.
Using the invert output with the Timer/Counter would mean you would have to use two channels, which might give you some nasty problems if the phase isn't 180º.
As an alternative, the ARM-based Arduino boards (Due, Zero, MKR series) have complementary output PWM channels. I don't know if the necessary microcontroller pins are brought out on the Arduino boards. You would have to check.