I am looking to iterate through cosmos db and store files(to archive) in blob storage in same format as separate files and not a big Json with all files in same JSON.

I tried to loop through cosmos DB via lookup ad then use copy activity in foreach :
ADF Pipeline

Below is the setting for Lookup:

LooKup

and then I used Copy activity within foreach :
ForEach setting:

@activity(‘Lookup1’).output.firstRow

Copy Activity Source setting:

Copy Activity Sink setting

• Error:
  the function length expects its parameter to be array or a string