ApolloError: Server response was missing for query ‘CreateChatbot’

I have successfully run my both front in nextJs and also run server stepzen start command

here is my serverClient.ts file

import {
  ApolloClient,
  DefaultOptions,
  HttpLink,
  InMemoryCache,
} from "@apollo/client";

const defaultOptions: DefaultOptions = {
  watchQuery: {
    fetchPolicy: "no-cache",
    errorPolicy: "ignore",
  },
  query: {
    fetchPolicy: "no-cache",
    errorPolicy: "all",
  },
  mutate: {
    errorPolicy: "all",
    fetchPolicy: "no-cache",
  },
};

export const serverClient = new ApolloClient({
  ssrMode: true,
  link: new HttpLink({
    uri: process.env.NEXT_PUBLIC_GRAPHQL_ENDPOINT,
    headers: {
      Authorization: `Apikey ${process.env.GRAPHQL_TOKEN}`,
    },
    fetch: typeof fetch !== "undefined" ? fetch : undefined,
  }),
  cache: new InMemoryCache(),
  defaultOptions,
});

here is apolloClient.ts file:

import {
  ApolloClient,
  DefaultOptions,
  InMemoryCache,
  createHttpLink,
} from "@apollo/client";

export const BASE_URL =
  process.env.NODE_ENV !== "development"
    ? `https://${process.env.NEXT_PUBLIC_VERCEL_URL}`
    : "http://localhost:3000";

const httpLink = createHttpLink({
  uri: `${BASE_URL}/api/graphql`,
});

const defaultOptions: DefaultOptions = {
  watchQuery: {
    fetchPolicy: "no-cache",
    errorPolicy: "ignore",
  },
  query: {
    fetchPolicy: "no-cache",
    errorPolicy: "all",
  },
  mutate: {
    errorPolicy: "all",
    fetchPolicy: "no-cache",
  },
};

const client = new ApolloClient({
  link: httpLink,
  cache: new InMemoryCache(),
  defaultOptions: defaultOptions,
});

export default client;

here is my mutations:

import { gql } from "@apollo/client";

export const CREATE_CHATBOT = gql`
  mutation CreateChatbot(
    $clerk_user_id: String!
    $name: String!
    $created_at: timestamptz!
  ) {
    insertChatbots(
      clerk_user_id: $clerk_user_id
      name: $name
      created_at: $created_at
    ) {
      id
      name
      created_at
    }
  }
`;

and here is handle where I have a simple input filed that I want to save my data inside neondb database and I have called this api using IBM API connection essential

  const { user } = useUser();
  const [name, setName] = React.useState("");
  const router = useRouter();

  const [createChatbot, { data, loading, error }] = useMutation(
    CREATE_CHATBOT,
    {
      variables: {
        clerk_user_id: user?.id,
        name: name,
        created_at: new Date().toISOString(),
      },
    }
  );

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    try {
      console.log("Creating Chatbot...");
      const data = await createChatbot();
      setName("");
      router.push(`/edit-chatbot/${data.data.insertChatbots.id}`);
    } catch (error) {
      console.error(error);
    }
  };

It’s look like I have done everything correctly, how it’s not save any data in the database always show me an error like this ApolloError: Server response was missing for query 'CreateChatbot'