The guide you posted tells you where to supply power (DC jack or Wago connector, 'Description..' section 2), and to connect the motors ('two output connectors' 'Description..' section 3, 'two pin motor output connector' under 'H Bridge motor interfacing')
As the chip is four half-bridges, each half bridge is controlled by an input (). I would imagine that the inputs labelled AL and BL are the half bridge inputs for the left motor and AR/BR the inputs for the right motor. They do not seem to have exposed the two EN inputs, so you won't be able to do free-wheeling PWM control, only switch between 'run' and 'brake'.
On this assumption, the effect of the inputs should be:
A B result
0 0 brake ( motor outputs both connected to ground )
1 0 forward ( one output at +ve, the other connected to ground )
0 1 reverse ( one output at +ve, the other connected to ground, opposite way round to above )
1 1 not used ( motor outputs both connected to +ve, should also brake )
You can PWM by switching between forward and brake, but it will result in more heating in the chip than PWM using the enable pin would. This is probably not a problem if the motor isn't close to the rating of the driver.