Spring bad Request 400

I've been trying to work on my simple Spring application, but when i got to the request, i always get a 400 code and i can't tell why. I provided below the Main,Controller and service classes. I double checked the path that i provided for the request, but still nothing. I also posted a picture on how the request looks like enter image description here

package com.example.greenbottle.customer;

import javax.persistence.*;
import java.time.LocalDate;

@Entity
@Table
public class Customer {
@Id
@SequenceGenerator(
        name = "customer_sequence",
        sequenceName = "customer_sequence",
        allocationSize = 1
)
@GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "customer_sequence"
)
private Long id;
private String name;
private String phoneNumber;
private LocalDate createdAt;

public Customer(String name, String phoneNumber,LocalDate createdAt) {
    this.name = name;
    this.phoneNumber = phoneNumber;
    this.createdAt = createdAt;
}

public Customer() {}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getPhoneNumber() {
    return phoneNumber;
}

public void setPhoneNumber(String phoneNumber) {
    this.phoneNumber = phoneNumber;
}

public LocalDate getCreatedAt() {
    return createdAt;
}

public void setCreatedAt(LocalDate createdAt) {
    this.createdAt = createdAt;
}

}

package com.example.greenbottle.customer;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping(path = "api/v2/customer")

public class CustomerController {
private final CustomerService customerService;

@Autowired
public CustomerController(CustomerService customerService) {this.customerService = 
customerService;}

@GetMapping
public List<Customer> getCustomers() {return customerService.getCustomers();}

@PostMapping
public void registerNewCustomer(@RequestBody Customer customer) 
{customerService.registerNewCustomer(customer);}

}

package com.example.greenbottle.customer;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;

import java.util.List;
import java.util.Optional;

@Service
public class CustomerService {
private final CustomerRepository customerRepository;

@Autowired
public CustomerService(CustomerRepository customerRepository) {this.customerRepository = customerRepository;}

public List<Customer> getCustomers() {
    return customerRepository.findAll();
}

public void registerNewCustomer(Customer customer) {
    customerRepository.save(customer);
}

}