Add apolloProvider in vue instance

main.js

// Create the apollo client
const apolloClient = new ApolloClient({
  link,
  cache: new InMemoryCache(),
  connectToDevTools: true
})

const apolloProvider = new VueApollo({
  defaultClient: apolloClient
})

new Vue({
  router,
  apolloProvider,
  apolloClient,
  render: h => h(App)
}).$mount('#app')