No Code JSON - Upload File Containing JSON Data

I am getting the below error message when trying to manually import a JSON file using the no-code JSON connector.

"Domo is ready, but there was an error parsing an expected JSON response from the API. Please check that the API is returning the expected data"

I am using a JSON account with no parameters other than the name of the account.

I am performing a number of steps to flatten out the data. The JSON is parsing well during this process (by the way this feature would be amazing if I could get it to work and would save hours working in Python).

Does anyone have an idea on how to fix it?

Many thanks