How to persist type List<String> in JPA

I'm trying to persist List , I failed to do. Entity :

@Entity(name = "carepost")
@Table(name = "carepost")
public class CarePost {
    @Id
    @GeneratedValue(strategy = GenerationType.TABLE)
    @Column(nullable = false, updatable = false)
    private Long idCarePost;

    private String code ;


     @ElementCollection
     @JsonFormat(with = JsonFormat.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY)
      private  List<@NotBlank String> service ;

and this is the API I save throw :

@PostMapping("/addcarepost")
public ResponseEntity<?> createCarePost(@RequestBody CarePost carePost){



    carePost.setCareserviceId(carePost.getCareserviceId());

    List<String> lstServices= new ArrayList<>();

    carePost.getService().forEach(item -> {
        lstServices.add(item);
    });

    carePost.setService(lstServices);


    carePostService.save(carePost);
    return ResponseEntity.ok(new MessageResponse("CarePost registered successfully!"));
}

I had error here :

Please any help can't fins solution for it

Error :

Postman request :