Problem when using structured response with OpenAI

[monkiki]

I'm trying to use the structured response API from OpenAI but always get this error:

org.springframework.ai.retry.NonTransientAiException: 400 - {
  "error": {
    "message": "Invalid schema for response_format 'custom_schema': In context=(), 'required' is required to be supplied and to be an array including every key in properties. Missing 'customer_address'.",
    "type": "invalid_request_error",
    "param": "response_format",
    "code": null
  }
}

This the sample code:

String text = "<text extracted from PDF invoice>";
String userPrompt = "Extract this invoice metadata in json format. The date fields need to be in \"yyyyMMddHHmmss\" format. " +
				"The fields to extract are described in the provided json schema."
String fullPrompt = userPrompt + " : " + text;
BeanOutputConverter<?> outputConverter = new BeanOutputConverter<>(InvoiceMetadata.class);
Prompt prompt = new Prompt(fullPrompt,
		OpenAiChatOptions.builder()
			.responseFormat(ResponseFormat.builder()
					.type(ResponseFormat.Type.JSON_SCHEMA)
					.jsonSchema(outputConverter.getJsonSchema())
					.build())
			.build());
ChatResponse response = chatModel.call(prompt);
return response.getResult().getOutput().getText();

This is the bean used to get the structured data:

@JsonIgnoreProperties(ignoreUnknown = true)
public static class InvoiceMetadata {
	public String invoice_number;
	public String invoice_date;
	public String invoice_amount;
	public String customer_cif;
	public String customer_name;
	public String customer_address;
}