The driver does not have some specific locked-antiphase mode since locked-antiphase is a control scheme that only depends on the signals you send to the driver. The way the driver interprets its own input pins does not need to change to accept that kind of control scheme. When I use the term “locked-antiphase mode”, I am simply referring to a scheme where you control the speed and direction of a motor with just one microcontroller pin by quickly changing the direction signal to the motor. The truth table for the driver shows that while PWM and INA are high the direction of the motor can be changed by simply toggling the INB pin.
Why do you want to use locked-antiphase control?