Invalid type for input: expected an array of objects. Please ensure the correct data format is used.

To fix the "Invalid type for 'messages': expected an array of objects, but got a string instead" error in the OpenAI API, you need to ensure that the messages parameter is correctly formatted as an array of objects. Here are the steps to resolve this issue:

Ensure your JSON variable or parameter is parsed correctly into a JSON object or array, rather than being treated as a string.

• Verify that the messages parameter is an array.

• Each element in the array should be an object with the required keys (e.g., role, content).

• Make sure there are no trailing or leading characters that could cause the JSON to be misinterpreted.

By correcting the data type and ensuring proper JSON parsing, you can resolve the 400 error and successfully make the API request.