Select count not working base in variable

Hi,
I want to pass the filename from parameter(pipeline-parameter) and check if that file is already loaded or not. If not loaded, then we go ahead to load it otherwise we do nothing.
Actually i have parent job and then this is child job , so pipeline parameter is from parent, it works fine without this file check step, so with file check step below is the issue:-
Below is the sql in snowflake execute
SELECT count(*) as cnt FROM FDR_SOURCE.KRONOS_LABORtest WHERE SOURCE_FILENAME = _Name
If i pass some fixed value, instead of _Name, then pipeline work fine. if i use param (_Name), it throws below error.

PLease see attached screenshot

Param set in “pipeline parameter”