How to catch server error?

[ujlm]

I have a custom API route which might throw an error when a user is not authenticated server-side. How to properly catch this error on the clients-side uploadToS3 function? Simply wrapping it in a try/catch function doesn't provide me with the error message sent from the server.

Client
const { url } = await uploadToS3(file, { endpoint: { request: { body, }, }, });

Server

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse
) {

  if (userIsNotAuthenticated) {
    return res
    .status(401)
    .json({ message: "User not authenticated" });
  }

  try {
    await uploadHandler(newReq as NextApiRequest, res);
  } catch (error) {
    return res
    .status(500)
    .json({ message: "S3 error" });
  }

}