[2843] Axios Plugin: window is not defined

I'm trying to access the Vuex store from the axios plugin but I'm getting a window is not defined error.

/plugins/axios.js

import * as axios from 'axios';

const options = {};
// The server-side needs a full url to works
if (process.server) {
  // options.baseURL = `http://${process.env.HOST || 'localhost'}:${process.env.PORT || 3000}`;
  options.baseURL = 'https://baseurl.com';
}

axios.interceptors.request.use((request) => {
  if (window.$nuxt.$store.state.userToken) {
    request.headers.Authorization = `Bearer ${window.$nuxt.$store.state.userToken.token}`;
  }
  return request;
}, (error) => {
  Promise.reject(error);
});

axios.interceptors.response.use(response => response, (error) => {
  // ERROR OCCURS HERE
  const authInstance = axios.create();
  // Do something with response error
  const request = error.config;
  if (window.$nuxt.$store.state.userToken && error.response && error.response.status === 401 && !request.retry) {
    request.retry = true;
    return axios.get(`https://baseurl.com/umbraco/api/auth/refreshtoken?token=${window.$nuxt.$store.state.userToken.token}`).then((response) => {
      window.$nuxt.$store.state.userToken = response.data;
      return authInstance(request);
    }).catch(() => {
      window.$nuxt.$store.dispatch('logout');
      window.location.replace('/');
    });
  }
  return Promise.reject(error);
});

export default axios.create(options);

/store/index.js

// eslint-disable-next-line
import Vue from 'vue';
import Vuex from 'vuex';
import axios from '~/plugins/axios';

Vue.use(Vuex);

const store = () => {
  const returnValue = new Vuex.Store({
    state: {
      userToken: null,
    },
    mutations: {
      SET_USER: function SET_USER(state, user) {
        // eslint-disable-next-line
        state.userToken = user;
      },
    },
    actions: {
      nuxtServerInit({ commit }, { req }) {
        if (req.session && req.session.userToken) {
          commit('SET_USER', req.session.userToken);
        }
      },
      login({ commit }, { username, password }) {
        return axios.post('/api/login', {
          username,
          password,
        }).then((res) => {
          if (res.status === 401) {
            throw new Error('Bad credentials');
          } else {
            return res;
          }
        }).then((userToken) => {
          commit('SET_USER', userToken);
        });
      },
      async logout({ commit }) {
        await axios.get('/api/logout').then(() => {
          commit('SET_USER', null);
        });
      },
    },
  });

  return returnValue;
};

export default store;

There error is occurring in the /plugins/axios.js on the response interceptor: axios.interceptors.response.use(response => response, (error) => {. It comes back as ReferenceError: window is not defined.