how to find REF ID after VC model migrated to BW7.3

Hi

Our DEV system is just upgraded to BW7.3, we do not use VC models oftern, only 2 models are being used.  I migrated the visual composer model to the new version.

I am having the problem to pass the data ,  in version 7.0 we use REF ID to pass the data in the assign value screen. eg.

LP_APPLICATION = #ID[ACACZ]@YAPPLICATION

ACACZ is REF ID for the element.

I can find at the bottom of the screen,

now after migration where can I find the REF ID for the element? do I have to install VC studio? thanks

Regards

Jia