A PWM scheme implementing synchronous switching is necessary. It would be also preferred due to lower losses.
I see three options:
1. standard 2-level (or bipolar) PWM.
Connect PWM to IRF2104 IN ports, one side inverted. Use SD to turn the driver off. Disadvantage: Higher ripple current.
2. standard 3-level (or unipolar) PWM.
Needs two phase shifted PWM signals, either generated by the controller or external logic
3. simplified unipolar PWM. Feed PWM signal to IN of one IRF2104 and connect the other IN to ground (low side permanently on). For direction reversal, flip the signals.