it works!

package-lock.json

@@ -8617,6 +8617,14 @@
         }
       }
     },
+    "html-parse-stringify2": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/html-parse-stringify2/-/html-parse-stringify2-2.0.1.tgz",
+      "integrity": "sha1-3FZwtyksoVi3vJFsmmc1rIhyg0o=",
+      "requires": {
+        "void-elements": "^2.0.1"
+      }
+    },
     "html-tags": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/html-tags/-/html-tags-2.0.0.tgz",
@@ -8790,6 +8798,14 @@
       "resolved": "https://registry.npmjs.org/hyphenate-style-name/-/hyphenate-style-name-1.0.3.tgz",
       "integrity": "sha512-EcuixamT82oplpoJ2XU4pDtKGWQ7b00CD9f1ug9IaQ3p1bkHMiKCZ9ut9QDI6qsa6cpUuB+A/I+zLtdNK4n2DQ=="
     },
+    "i18next": {
+      "version": "19.3.4",
+      "resolved": "https://registry.npmjs.org/i18next/-/i18next-19.3.4.tgz",
+      "integrity": "sha512-ef7AxxutzdhBsBNugE9jgqsbwesG1muJOtZ9ZrPARPs/jXegViTp4+8JCeMp8BAyTIo1Zn0giqc8+2UpqFjU0w==",
+      "requires": {
+        "@babel/runtime": "^7.3.1"
+      }
+    },
     "iconv-lite": {
       "version": "0.4.24",
       "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.24.tgz",
@@ -14234,6 +14250,15 @@
       "resolved": "https://registry.npmjs.org/react-error-overlay/-/react-error-overlay-6.0.7.tgz",
       "integrity": "sha512-TAv1KJFh3RhqxNvhzxj6LeT5NWklP6rDr2a0jaTfsZ5wSZWHOGeqQyejUp3xxLfPt2UpyJEcVQB/zyPcmonNFA=="
     },
+    "react-i18next": {
+      "version": "11.3.4",
+      "resolved": "https://registry.npmjs.org/react-i18next/-/react-i18next-11.3.4.tgz",
+      "integrity": "sha512-IRZMD7PAM3C+fJNzRbyLNi1ZD0kc3Z3obBspJjEl+9H+ME41PhVor3BpdIqv/Rm7lUoGhMjmpu42J45ooJ61KA==",
+      "requires": {
+        "@babel/runtime": "^7.3.1",
+        "html-parse-stringify2": "2.0.1"
+      }
+    },
     "react-is": {
       "version": "16.13.1",
       "resolved": "https://registry.npmjs.org/react-is/-/react-is-16.13.1.tgz",
@@ -17099,6 +17124,11 @@
       "resolved": "https://registry.npmjs.org/vm-browserify/-/vm-browserify-1.1.2.tgz",
       "integrity": "sha512-2ham8XPWTONajOR0ohOKOHXkm3+gaBmGut3SRuu75xLd/RRaY6vqgh8NBYYk7+RW3u5AtzPQZG8F10LHkl0lAQ=="
     },
+    "void-elements": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/void-elements/-/void-elements-2.0.1.tgz",
+      "integrity": "sha1-wGavtYK7HLQSjWDqkjkulNXp2+w="
+    },
     "vue": {
       "version": "2.6.11",
       "resolved": "https://registry.npmjs.org/vue/-/vue-2.6.11.tgz",

package.json

@@ -8,9 +8,11 @@
     "@testing-library/react": "^10.0.1",
     "@testing-library/user-event": "^10.0.0",
     "axios": "^0.19.2",
+    "i18next": "^19.3.4",
     "lodash": "^4.17.15",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
+    "react-i18next": "^11.3.4",
     "react-markdown": "^4.3.1",
     "react-scripts": "3.4.1",
     "react-toastify": "^5.5.0",

src/components/LeftSidebar/tabs/Profile.js

@@ -1,11 +1,16 @@
 import React from 'react';
+import { useTranslation } from 'react-i18next';
+
 import TextField from '../../../shared/TextField';
 
-const ProfileTab = ({ data, onChange }) => (
+const ProfileTab = ({ data, onChange }) => {
+  const { t } = useTranslation();
+
+  return (
     <div>
       <TextField
         className="mb-6"
-      label="Photo URL"
+        label={t('profile.photoUrl')}
         placeholder="https://i.imgur.com/..."
         value={data.profile.photo}
         onChange={v => onChange('data.profile.photo', v)}
@@ -89,5 +94,7 @@ const ProfileTab = ({ data, onChange }) => (
         onChange={v => onChange('data.profile.email', v)}
       />
     </div>
-);
+  );
+};
+
 export default ProfileTab;

src/i18n/index.js

@@ -0,0 +1,19 @@
+import i18n from 'i18next';
+import { initReactI18next } from 'react-i18next';
+
+import leftSidebarEn from './locales/en/leftSidebar.json';
+
+i18n.use(initReactI18next).init({
+  lng: 'en',
+  fallbackLng: 'en',
+  debug: true,
+  resources: {
+    en: {
+      translations: leftSidebarEn,
+    },
+  },
+  ns: ['translations'],
+  defaultNS: 'translations',
+});
+
+export default i18n;

src/i18n/locales/en/leftSidebar.json

@@ -0,0 +1,5 @@
+{
+  "profile": {
+    "photoUrl": "Photo URL"
+  }
+}

src/index.js

@@ -3,6 +3,7 @@ import ReactDOM from 'react-dom';
 import { toast } from 'react-toastify';
 import 'react-toastify/dist/ReactToastify.css';
 
+import './i18n';
 import './assets/tailwind/tailwind.css';
 import './index.css';