Spring boot using Postman returning null when making a POST with foreign key

I'm using POSTMAN and trying to do a post request with Spring Boot. I have an OneToOne relationship between "paciente" and "Operativo". When i try to create an "Operativo" instance with Postman, all the "paciente" attributes asociated with that "Operativo" are null. I don't know if it's problem of the relationship in the models, the controller or something else.

Relation in "paciente" model

@Entity
@Table(name = "Paciente")
public class paciente {
    @Id
    private long rut;

    private String nombre;
    private String nacionalidad;
    private String sexo;
    private String fecha_na;
    private String domicilio;
    private String diagnostico;
    private String telefono;
    private String gravedad;
    @OneToOne(mappedBy = "paciente")
    private Operativo operativo;
   

Relation in "Operativo" model

@Entity
@Table(name = "Operativo")
public class Operativo{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;

    private String dia;
    private String hora;
    private String equipamiento;
    private String equipo;
    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "paciente", referencedColumnName  = "rut")

    public paciente paciente;

OperativoController

@RestController
@CrossOrigin
@RequestMapping("/api/Operativo")

public class OperativoController{
    @Autowired
    private operativoService operativoService;
    @GetMapping("")
    public Iterable<Operativo> getOperativos(){
        return operativoService.listAll();
    }
    @PostMapping("")
    public ResponseEntity<Operativo> addOperativo (@RequestBody Operativo operativo){
        Operativo ope= operativoService.saveOrUpdateOperativo(operativo);
        return new ResponseEntity<Operativo>(ope,HttpStatus.CREATED);
    }
    
}

operativoService

@Service
public class operativoService{
    @Autowired
    private OperativoRepository operativoRepository;
    public Operativo saveOrUpdateOperativo(Operativo operativo){
        return operativoRepository.save(operativo);
    }
    public Iterable<Operativo> listAll(){
        return operativoRepository.findAll();
    }
    public  void deleteOperativo(int id){
        operativoRepository.deleteById(id);
    }
    public Operativo getOperativoById(int id){
        return operativoRepository.findById(id);
    }
    
}

POSTMAN post input

{
    "id" : 1,
    "equipamiento" : "o",
    "equipo" : "a",
    "hora":"a",
    "dia": "a",
    "paciente": {"rut":123123}
}

POSTMAN Output

{
    "id": 1,
    "dia": "a",
    "hora": "a",
    "equipamiento": "o",
    "equipo": "a",
    "paciente": {
        "rut": 123123,
        "nombre": null,
        "nacionalidad": null,
        "sexo": null,
        "fecha_na": null,
        "domicilio": null,
        "diagnostico": null,
        "telefono": null,
        "gravedad": null
    }
}

1.First thing you don't need referencedColumnName when we are with one to one relationship.
2.Your postman input to be given for "paciente". Above we are seeing only one column data. You have to give input for all neccesary values u need

Finally i fixed my problem, changing this line of code on "Operativo" relation

 @JoinColumn(name = "paciente", referencedColumnName  = "rut")

to

@JoinColumn(name = "rut")

It seems that "name" attribute should match the name of the foreign key that i'm referencing, instead of the name of the entity referenced.

Now using this POSTMAN Input.

{"id":1 ,
"dia":"asd",
"hora":"asd",
"equipamiento":"asd",
"equipo":"asd",
"paciente":{"rut":19}}

I get the following Output

{
    "id": 1,
    "dia": "asd",
    "hora": "asd",
    "equipamiento": "asd",
    "equipo": "asd",
    "paciente": {
        "rut": 19,
        "nombre": "asd",
        "nacionalidad": "asd",
        "sexo": "asd",
        "fecha_na": "asd",
        "domicilio": "asd",
        "diagnostico": "asd",
        "telefono": "asd",
        "gravedad": "asd"
    }
}

Also removed @OneToOne(cascade = CascadeType.ALL) in the "Operativo" class, because it was causing that when i create an "Operativo", it also creates the "Paciente" entity with the given data. So, when creating an "Operativo" if i give it only "paciente":{"rut":19} in the JSON, it will create a "Paciente" with only that attribute and all the others will be null.