我不认为是服务器端的问题，请按照这段代码从您的appoloclient它的工作e

import {
  ApolloClient,
  HttpLink,
  ApolloLink,
  InMemoryCache,
  concat,
  split,
} from "@apollo/client"
import AsyncStorage from "@react-native-async-storage/async-storage"

import { WebSocketLink } from "@apollo/client/link/ws"
import { SubscriptionClient } from "subscriptions-transport-ws"
import { getMainDefinition } from "@apollo/client/utilities"

let token: string | null = null

const getToken = async () => {
  return new Promise(async (resolve) => {
    try {
      let value = await AsyncStorage.getItem("token")
      console.log("token", value)
      console.log("Done.")
      token = value
      resolve(value)
    } catch (e) {
      // read error
    }
  })
}

const URL = "a2db-130-193-219-4.ngrok.io"

const httpLink = new HttpLink({
  uri: https://${URL}/graphql,
})

const wsLink = new WebSocketLink({
  uri: wss://${URL}/graphql,
  options: {
    reconnect: true,
  },
})

getToken()

const authMiddleware = new ApolloLink((operation, forward) => {
  // add the authorization to the headers
  operation.setContext({
    headers: {
      authorization: ${token || ""},
      "Content-Type": "application/json",
    },
  })

  return forward(operation)
})

const splitLink = split(
  ({ query }) => {
    const definition = getMainDefinition(query)
    return (
      definition.kind === "OperationDefinition" &&
      definition.operation === "subscription"
    )
  },
  wsLink,
  httpLink
)

const client = new ApolloClient({
  cache: new InMemoryCache(),
  link: concat(authMiddleware, splitLink),
})

export default client

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您需要添加第二个前端作为允许的来源，例如，如果第二个前端是从http：//localhost：3001提供的，请执行以下操作：

cors({ 
  origin: ["http://localhost:3000", "http://localhost:3001"], 
  credentials: true
})

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如果你想允许所有的原点，你可以设置origin: true。
在这里查看所有允许的origin选项：
https://www.npmjs.com/package/cors#configuration-options