Extended buffer to buffer credits activation on a cisco MDS 9250i

We have a few MDS 9250i switches, ready to replace a couple of 9222i switches and because of long distance links and the distance between the data centers, we would like to use extended buffer credits. The 9250i switches should be able to supply these credits and yes, we have the enterprise license installed on the switches. But we seem unable to get these buffer credits configured on the E ports.

Does anyone know the steps to actually configure extended B2B credits to a port?