Can we or should we parallel H-bridge module for increse current?
It is bad practice to blindly parallel drivers without knowing how to estimate the power dissipation and heat rise.
Generally you choose drivers and heatsinks so that they are capable of driving the DCR coil resistance for surge starts with much less voltage drop than the DCR.  Your MOSFET H bridge specs are:

Output current: IOUT = 1.2 A(ave)/3.2 A (peak)
Output low ON resistor: 0.5Ω (upper+lower Typ. @ VM ≥ 5 V)

Therefore the motor DCR must be matched to the driver. 3.2A peak implies a ratio of I=Vbat/(2Ron+DCR). Since there are two FETs active , it is 2Ron.
If you need more current, consider a better bridge driver instead.  6644 family and up instead of 6612