TC: VTRC - Set up Meta Data (Customize function module)

For few business requirements we have decided to customize the standard function module in "meta data setup" in VTRC transaction. During the analysis i have put the break point in the function module. System is not stopping at that point when i am executing transactions in foreground.

I came to know that we have to activate few settings, so that system will stop at that break point level. Could any body let me know what are these settings?

Thanks & Regards