code: public ExternalID getPersonExternalIds(int personId) throws MovieDbException {
          TmdbParameters parameters = new TmdbParameters();
          parameters.add(Param.ID, personId);
  
          URL url = new ApiUrl(apiKey, MethodBase.PERSON).subMethod(MethodSub.EXTERNAL_IDS).buildUrl(parameters);
          String webpage = httpTools.getRequest(url);
  
          try {
              return MAPPER.readValue(webpage, ExternalID.class);
          } catch (IOException ex) {
              throw new MovieDbException(ApiExceptionType.MAPPING_FAILED, "Failed to get person external IDs", url, ex);
          }
      }
docs: Get the external ids for a specific person id.
  
  @param personId
  @return
  @throws MovieDbException