Schema Mapper and embedded PostgreSQL connection parameters

When using the schema mapper and connecting to a postgres table and choosing embedded connections there are no options to choose a parameter that holds the relevant value.

For host, port, database and username, I'm able to type e.g. $(STAGING_DB) and create the link to my user parameter that way. However this doesn't work for the password field.

Is there any trick to link the password parameter?

(FME 2021.2.0.0 Build 21784)