Answers for "what status should i send with error message"

http response

resource HTTP response method is made up of three
components:
Response Status Code ==> 200, 301, 404, 500
(these are the most common ones)
Response Header Fields ==> Date, Server, LastModified, Content-Type
Response Body ==> This is the data that comes
back to the client from the server.

200 error code

The HTTP 200 OK success status response code indicates that the request has succeeded. A 200 response is cacheable by default. The meaning of a success depends on the HTTP request method: GET : The resource has been fetched and is transmitted in the message body.

from developer.mozilla.org