Textjoin or concat - Simplify my table, eliminate typo mistakes and manual searching

How do I use a textjoin formula to search for a "detail", verify the net column is >0, then output / display the respective Table in the respective "Item" row?

i.e., per attached table

=TEXTJOIN(",",TRUE,IF(LOOKUP($B$3:$B$38=J6,$F$3:$F$38>0,""),$A$3:$A$38,""))