Error [vuex] unknown action type: login

Hi all, i don't understand why return it:

[vuex] unknown action type: login

index.js

import Vue from 'vue'
import Vuex from 'vuex'
import auth from "./auth";

Vue.use(Vuex)
export default new Vuex.Store({
state: {
// TODO
},
mutations: {
// TODO
},
actions: {
// TODO
},
modules: {
auth
}
})

auth.js

import axios from 'axios'

export default ({
namespaced: true,
state: {
token: null,
user: null
},
mutations: {
// TODO
},
actions: {
async login(_, credentials) {
let response = await axios.post('/login', credentials)
//
console.log(response.data);
}
},
})

main.js

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'
import axios from 'axios'

axios.defaults.baseURL = 'http://laravel_api.local/api/'
Vue.config.productionTip = false
new Vue({
router,
store,
render: h => h(App)
}).$mount('#app')

Login.vue

<form @submit.prevent="submit">
    <div>
        <label> Email </label>
        <input type="text" name="email" id="email" v-model="form.email">
    </div>
    <div>
        <label> Password </label>
        <input type="password" name="password" id="password" v-model="form.password">
    </div>
    <div>
        <button type="submit">sign in</button>
    </div>
</form>

    import { mapActions } from 'vuex'
export default {
    name: 'login',

    components: {
        //
    },
    data() {
        return {
            form: {
                email: '',
                password: ''
            }
        }
    },
    methods: {
          ...mapActions({
              login: 'login'
          }),

        submit () {
              this.login(this.form)
        }
    }
}