```js
import { I18n } from 'aws-amplify';
import { translations } from '@aws-amplify/ui-react';
I18n.putVocabularies(translations);
I18n.setLanguage('fr');

I18n.putVocabularies({
  fr: {
    'Sign In': 'Se connecter',
    'Sign Up': "S'inscrire",
  },
  es: {
    'Sign In': 'Registrarse',
    'Sign Up': 'Regístrate',
  },
});
```