How do debug BBP_ECS_PO_OUT_BADI?

Hi Experts.

SRM 4.0, backend ECC 6.0.

I know how to debug in SRM using the web-debugger, but has anyone tried to debug this BAdI? As far as I can tell when debugging the creation of a shopping cart, this function is called after this. I cannot reach this, so how would you debug it? Any ideas would be highly appreciated.

Thanks.