Failed to send "face_recognition/id" in opencv to home assistant via mqtt

Configuration
1

I have successfully installed opencv and can broadcast on localhost pc, but I failed to connect the opencv that I installed on the PC, with the home assistant server that I installed on the raspberry pi 4 via mqtt. I only want to broadcast face_id so as not to burden the performance of my raspberry pi4. Next in the home assistant I added the “Face Recognition ID”

mqtt:
sensor:
- name: "Face Recognition ID"
state_topic: "face_recognition/id"
value_template: "{{ value_json.face_id }}"

then in opencv I added the following code:

import paho.mqtt.client as mqtt  
import json  

# Konfigurasi MQTT  
broker = "localhost"  # Ganti dengan IP Raspberry Pi Anda jika perlu  
port = 1883  # Port default untuk MQTT  
topic = "face_recognition/id"  # Topik untuk mengirim ID  

# Fungsi callback saat terhubung ke broker  
def on_connect(client, userdata, flags, rc):  
    if rc == 0:  
        print("Terhubung ke broker dengan hasil kode: " + str(rc))  
    else:  
        print("Gagal terhubung, hasil kode: " + str(rc))  

# Membuat client MQTT  
client = mqtt.Client(client_id="", clean_session=True, userdata=None, protocol=mqtt.MQTTv311)  
client.on_connect = on_connect  

# Mengatur username dan password untuk otentikasi  
client.username_pw_set("jhondoe", "1234")  # Ganti dengan username dan password yang sesuai  

# Menghubungkan ke broker  
client.connect(broker, port, 60)  

# Fungsi untuk mengirim ID wajah  
def send_face_id(face_id):  
    payload = {  
        "face_id": face_id  
    }  
    client.publish(topic, json.dumps(payload))  
    print(f"ID wajah {face_id} telah dikirim ke topik {topic}")  

# Contoh penggunaan  
if __name__ == "__main__":  
    client.loop_start()  # Memulai loop untuk mendengarkan pesan  
    try:  
        while True:  
            face_id = input("1,2,3,4,  (atau 'exit' untuk keluar): ")  
            if face_id.lower() == 'exit':  
                break  
            send_face_id(face_id)  
    except KeyboardInterrupt:  
        pass  
    finally:  
        client.loop_stop()  # Menghentikan loop  
        client.disconnect()  # Memutuskan koneksi

the second problem is the status of the “Face Recognition ID” sensor is always Unknown. thank you