How to use data storage input of text

Im having a problem with a command that I want to use, its a macro and uses storage called "file". what I want to do is replace this with text from a command not pointing to an nbt source if possible.
$execute as @s[tag=small_room_north] at @s run place template dgen:level/$(file)/small_room_north This is the macro code, and I wanted to replace the file with text from this command data modify storage file text set value "demo". This I was hoping to output a file path to dgen:level/demo/small_room_north but instead got this error. This is another command calling on the macro function execute as @e[tag=main_room] as @n[sort=nearest,limit=1,tag=!main_room,tag=clear] run function dgen:generation/base_gen/v1/place with storage file.