Revalidation for data using next.js 15 route handlers

  useEffect(() => {
    const fetchClients = async () => {
      const response = await fetch("/api/clients", { next: { tags: ['clients'] } });
      const data = await response.json();
      setClientCells(data);
    };
    fetchClients();
  }, []);

 const submitHandler = async (data: ClientFormData) => {
     const response = await fetch("/api/clients", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(data),
      });
      revalidateTag("clients")
      reset();
      setFiles([]);
  };
  const onSubmit = handleSubmit(submitHandler);

  return(
      <form
       onSubmit={onSubmit}
       className="px-10 space-y-5 my-4">
      .....
     </form>
  )

export async function POST(req: NextRequest) {
  try {
    const body = await req.json();
    const parsedBody = clientSchema.safeParse(body);
    const client = await prisma.clients.create({
      data: parsedBody.data,
    });
    return NextResponse.json(
      { message: "Client created successfully", client },
      { status: 201 }
    );
  } catch (error) {
    return NextResponse.json(
      { error: "An unexpected error occurred while creating the client." },
      { status: 500 }
    );
  }
}