Rest API response to a single valid JSON

I have a copy activity in pipeline which is reading data from Rest API source and sink is a JSON file to data lake. The output is paginated and when saved in storage forms an invalid JSON. On search I found in stackoverflow mentioning to set File Pattern as Array of Objects in dataflow mappings. In my case it is a simple copy activity with no mapping data flows but I see the same property which I tried but no luck. Can anyone advise what am I missing?