how to update e register model on top of PCIe

I want to config a device register through PCIe interface, I would like to use vr_ad_sequence not vr_pcie_tl_sequence. I basically built vr_ad e register model on top of pcie eVC and create the vr_ad_execute_op() by calling the mem_write() and mem_read(), the vr_ad_seqence is working.

but to udpate e register  model, I don't know how to implement it. I tried extend PASSIVE vr_pcie_tl_monitor, on in_trans_ended, I udpated the e reg model by using cur_in_trans pkt. However, when I load the e file, it says , cur_in_trans.as_a(MWR REQ vr_pcie_tl_pkt).data cannot be accessed.

In MWR REQ vr_pcie_tl_pkt, data field is there. Can anyone please tell me how to update the reg model on top of PCIe? Thanks.