curl "https://api.phrase.com/v2/projects/:project_id/locales/:id" \
  -u USERNAME_OR_ACCESS_TOKEN \
  -X PATCH \
  -d '{"branch":"my-feature-branch","name":"de","code":"de-DE","source_locale_id":"abcd1234abcd1234abcd1234abcd1234"}' \
  -H 'Content-Type: application/json'

{
  "id": "abcd1234cdef1234abcd1234cdef1234",
  "name": "de",
  "code": "de-DE",
  "default": true,
  "main": false,
  "rtl": false,
  "plural_forms": [
    "zero",
    "one",
    "other"
  ],
  "ordinal_plural_forms": [
    "zero",
    "other"
  ],
  "source_locale": {
    "id": "abcd1234cdef1234abcd1234cdef1234",
    "name": "en",
    "code": "en-GB"
  },
  "fallback_locale": {
    "id": "abcd1234cdef1234abcd1234cdef1234",
    "name": "en",
    "code": "en-GB"
  },
  "created_at": "2015-01-28T09:52:53Z",
  "updated_at": "2015-01-28T09:52:53Z",
  "statistics": {
    "keys_total_count": 2120,
    "keys_untranslated_count": 100,
    "words_total_count": 3102102,
    "translations_completed_count": 1920,
    "translations_unverified_count": 32,
    "unverified_words_count": 129,
    "missing_words_count": 3920
  }
}