Join Table with extra column - oop

Question

In my spring boot application I have user model, type model and user_type. Here a join table is created in the user model as user_type.
Model in maven project with jpa :
package com.example.pharmanic.model;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.*;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Size;
#Entity
#Table( name = "users",
uniqueConstraints = {
#UniqueConstraint(columnNames = "username"),
#UniqueConstraint(columnNames = "email")
})
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotBlank
#Size(max = 20)
private String username;
#NotBlank
#Size(max = 50)
#Email
private String email;
#NotBlank
#Size(max = 120)
private String password;
**#ManyToMany(fetch = FetchType.LAZY)
#JoinTable( name = "user_roles",
joinColumns = #JoinColumn(name = "user_id") ,
inverseJoinColumns = #JoinColumn(name = "role_id")
)**
private Set<Role> roles = new HashSet<>();
public User() {
}
public User(String username, String email, String password) {
this.username = username;
this.email = email;
this.password = password;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Set<Role> getRoles() {
return roles;
}
public void setRoles(Set<Role> roles) {
this.roles = roles;
}
}
The join table user_role has two columns; user_id & role_id.
I want to add an extra column to user_role table to save more data relevant to user_role. A type String column should be added to the user_role table.