Spring boot JPA - What is the best solution for updating the intermediate table of ManyToMany relationship with extra columns in the Controller?

Question

I am using Spring Boot for backend in my project. In the database (MySQL) I have a many-to-many relationship which has the next entities: User, interest and relUserInterest. The RelUserInterest is a intermediate table between User and Interest and has extra columns.

User Entity

@Entity
public class User {

    @Id @GeneratedValue private Long id;
     
    @NotNull
    @Column (unique = true) private String email;

    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL)
    @NotNull
    Set<RelUserInterest> priority = new HashSet<>();

    // more attributes, constructor, get and set
}

Interest entity

@Entity
public class Interest {
    @Id
    @GeneratedValue
    private long id;

    @NotEmpty
    @Column(unique = true)
    private String nameInterest;

    @OneToMany(mappedBy = "interest", cascade = CascadeType.ALL)
    @NotNull
    Set<RelUserInterest> priority = new HashSet<>();

    // more attributes, constructor, get and set
}

RelUserInterest entity

@Entity
@Table(name = "rel_user_interest")
@IdClass(UserInterestId.class)
public class RelUserInterest implements Serializable {

    @Id
    @ManyToOne
    @JoinColumn(name = "user_id", referencedColumnName = "id")
    User user;

    @Id
    @ManyToOne
    @JoinColumn(name = "interest_id", referencedColumnName = "id")
    Interest interest;

    int priority;

    //  constructor, get and set
}

So far so good. I want to update the user and their interests. My controller is this. I want to do is when I update a existing user, update the intermediate table (RelUserInterest).

@PutMapping("/update/{id}")
    public ResponseEntity<?> updateUser(@Validated @RequestBody UserDTOUpdate userDTOUpdate, BindingResult result, @PathVariable Long id) {
        // More code
        User user = usersService.getUserById(id);
        
        // Code updating other attributes

        // Here this the problem --> I don't know how to update the attribute priority of RelUserInterest

        usersService.updateUser(user);
        return new ResponseEntity<>(new Mensaje("Usuario actualizado"), HttpStatus.CREATED);
    }

I have found several links but I'm not sure which is the best solution and I don't know how do it with my code.

• How to update ManyToMany with extra columns
• Spring boot JPA many to many with extra column insert and update issue
• Spring-Data-JPA ManyToMany relationship with extra column

In the Postman i want to send the next JSON although the interest array can be different if it is necessary for the solution:

{
    "age": 22,
    "genre": "Male",
    "userName": "Miguel",
    "roles": [
        "ROLE_ADMIN",
        "ROLE_USER"
    ],
    "interest": [
        {
            "interestID": 1,
            "nameInterest": "Museum",
            "priority": 9
        }
    ]
}

Question

So, the question is: How can I update the attribute priority of the RelUserEntity table? I suppose that making an intermediate table repository is a mistake. I'm a little lost. I hope you can help me. Thank you.