We carry a few different versions of the dual MC33926 motor driver carriers, but it sounds like you might be referring to the Dual MC33926 Motor Driver for Raspberry Pi. The Dual MC33926 Motor Driver for Raspberry Pi does not have anything specific onboard for supporting encoders. It does break out the Raspberry Pi GPIO pins; however, I suspect it might be difficult to read encoder signals reliably with the Raspberry Pi since it does not have a real-time operating system.
You might consider using a separate microcontroller, like an Arduino or one of our Arduino-compatible A-Star 32U4 Programmable Controllers, to read the encoder signals. If you could use a smaller, less powerful motor, such as one of our 12V Medium-Power 25D Gearmotors, something like our A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge might be a good choice: