Pagerequest object with sort property of the child - spring-data-jpa

Question

How to specify the children's property name while creating the PageRequest object. In the below example, I want to sort based on the name property of the Customer entity which is part of the Order class. I should be able to sort on any of the parent or child field.
Sort.Direction sortDirection = direction
.equalsIgnoreCase("asc") ? Sort.Direction.ASC : Sort.Direction.DESC;
//how to make the `name` property map to `Customer` name
PageRequest pageRequest = PageRequest.of(page, size, sortDirection, "name");
Page<Order> pageResponse = this.orderRepository.findAll(pageRequest);
#Entity
#Table(name = "orders")
public class Order {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#ManyToOne
#JoinColumn(name="customer_id", nullable = false)
#JsonBackReference
private Customer customer;
...
----------
#Entity
#Table(name = "customers")
#NoArgsConstructor
public class Customer implements UserDetails {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#NotEmpty(message = "customer name cannot be empty")
private String name;
#OneToMany(mappedBy = "customer", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#JsonManagedReference
private Set<Order> orders;
...