How to fetch redis cli set json and fetch from Get Api Spring boot redis?

I want response from redis cli to postman as this

http://localhost:8585/api/home/getBestTrainerBasedRating

[
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 0.0,
        "image": "null",
        "language": "kannada"
    },
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 0.0,
        "image": "null",
        "language": "telugu"
    },
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 6.0,
        "image": "null",
        "language": "kannada"
    },
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 6.0,
        "image": "null",
        "language": "telugu"
    },
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 10.0,
        "image": "null",
        "language": "kannada"
    },
    {
        "trainerid": 28,
        "rating": 5.0,
        "trainerName": "yellow",
        "courseName": "",
        "price": 10.0,
        "image": "null",
        "language": "telugu"
    }
]

But I am getting this response http://localhost:8585/api/redishome/redisGetBestTrainerBasedRating

{
    "message": "Null key returned for cache operation (maybe you are using named params on classes without debug info?) Builder[public java.util.List com.mycareerbuild.user.cache.HomeControllerCache.getBestTrainerBasedRatingFromRedis()] caches=[homeCache] | key='#getratinghome' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'"
}

This is my Controller

   @RestController
  @RequestMapping("/api/redishome")
  public class HomeRedisController {
  @Autowired
  HomeControllerCache hc;
  @Autowired
 private HomeService homeService;
 private static final Logger logger = LogManager.getLogger(HomeRedisController.class);
@GetMapping("/redisGetBestTrainerBasedRating")
@ResponseBody
 public ResponseEntity<List<BestTrainerBasedRating>> RedisgetBestTrainerBasedRating()
    throws RecordNotFoundException {
 logger.info("started RedisgetBestTrainerBasedRating method in controller");
List<BestTrainerBasedRating> trainerCourse = hc.getBestTrainerBasedRatingFromRedis();
logger.info("end RedisgetBestTrainerBasedRating method in controller");
return new ResponseEntity<List<BestTrainerBasedRating>>(trainerCourse, new HttpHeaders(), 
 HttpStatus.OK);
 }}

this is my cache component

 @Component
   public class HomeControllerCache {
    @Autowired
    HomeControllerCacheRepo cacheRepo;

        @Autowired
        private HomeRepository homeRepo;
    @Cacheable(value="homeCache" ,key="#getratinghome")
        public List<BestTrainerBasedRating> getBestTrainerBasedRatingFromRedis() {
    List<BestTrainerBasedRating> ratingD = null;
    try {
         ratingD = cacheRepo.getBestTrainerBasedRating();
       } catch (Exception e) {
         e.printStackTrace();
             }
            return ratingD;
      } }

this is my cache repo

  @Repository
  public class HomeControllerCacheRepo {

 public static final String KEY = "HOME";
  
    private RedisTemplate<String, BestTrainerBasedRating> redisTemplate;
  [enter image description here][1]  private HashOperations hashOperations;
   
    public HomeControllerCacheRepo(RedisTemplate redisTemplate) {
        this.redisTemplate = redisTemplate;
        this.hashOperations = redisTemplate.opsForHash();
    }
 
   /*Getting a specific item by item id from table*/
    public  List<BestTrainerBasedRating> getBestTrainerBasedRating(){
        return  (   List<BestTrainerBasedRating>) hashOperations.get(KEY, hashOperations);
    }}

I have attached redis cli image please check