You would get the same error locally by building it with next build.

Route Handlers have a different signature with App Router, see the official docs. If you rely on your response, try awaiting it from the request as follows:

export const POST = async (req: NextRequest) => {
  const data = await req.json();
  const { params } = await data as MyResponse;

  if (!params || !params.action)
    return NextResponse.json({ success: false, message: "Incorrect usage" });

  const action = params.action;
  ...
};