Cannot set property $backendConnector of [object Object] which has only a getter

I'm trying to use a service globally in my Nuxt app. I've created my service, put it in a plugins and called it in my nuxt config, but I get this error. I'm not sure how to make it works.

services/backendConnector.js

const backendConnector = {
  getReviews() {
    return fetch(`${baseUrl}/reviews`);
  },
  more functions like this one ...
}

export default backendConnector;

/plugins/backendConnector.plugin.js

// eslint-disable-next-line import/no-extraneous-dependencies
import Vue from 'vue';
import backendConnector from '@/services/backendConnector';

Vue.prototype.$backendConnector = backendConnector;

nuxt.config.js

plugins: [
    '@/plugins/backendConnector.plugin.js',
]