CSV Processor error: The custom liquid terminates in an object of class String.

[gauri]

I have a JSON data that I am tryign to write to a csv file. but keep receiving this error - The custom liquid terminates in an object of class String..

The "test_array" is set to "test1":123, "test1", 456

Here's the settigns of the task:

Processor: CSV

Liquid Input: {{Data.Liquid.test_array | to_json}}