CAN FD change BRP (Prescaler)

Hi,
I am using a 2 Channel CAN BUS FD shield for Raspberry Pi.
I am trying to configure CAN FD using “ip link”. I have tried configurations with different sample point, prop-seg, phase-seg1, phase-seg2 and sjw. But I get FIFO overrruns, probably due to bit timings slightly incorrect

However, there are some values I cannot reach due to the prescaler or BRP.

Can someone tell how to set/change the value of the brp and dbrp?

Thank you.