Nginx reverse proxy [error] connect() failed (111: Connection refused) while connecting to upstream, docker-compose

Question

Im trying to set a reverse_proxy with nginx

i'm using image docker of nginx and back-end servers that I'm trying to reach by the reverse_proxy are an application angular i did a dockerfile of that app and i have also a API as image i did docker file for it also I created a docker compose but i after i run docker-compose up it happens that only only the API (called folwable-ui) works but the application of angular give a response of 502 Bad Gateway nginx/1.23.0

here is my docker compose

services:
  reverseproxy:
    build:
      context: .
      dockerfile: nginx.Dockerfile
    ports:
      - "443:443" 
      - "80:80" 
    restart: always
    volumes:
      - ./nginx/conf/:/etc/nginx/conf.d/:ro
  postgres:
    depends_on:
      - reverseproxy 
    build:
      context: .
      dockerfile: postgres.Dockerfile
    environment:
      - POSTGRES_USER=flowable
      - POSTGRES_PASSWORD=flowable
      - POSTGRES_DB=flowable
      - POSTGRES_HOST_AUTH_METHOD=password  
    ports:
      - "15432:5432"  
    restart: always
  flowableui:
    depends_on:
      - postgres
    build:
      context: .
      dockerfile: flowable.Dockerfile
    environment:
      - SPRING_DATASOURCE_DRIVER-CLASS-NAME=org.postgresql.Driver
      - SPRING_DATASOURCE_URL=jdbc:postgresql://host.docker.internal:15432/flowable
      - SPRING_DATASOURCE_USERNAME=flowable 
      - SPRING_DATASOURCE_PASSWORD=flowable 
    ports:
      - "8080:8080"  
    restart: always
  angularboite:
      depends_on:
        - flowableui
        - reverseproxy
      build:
        context: ./BoiteATacheTemplate
        dockerfile: Dockerfile
      ports:
        - 4200:4200

and here is my nginx.conf file :

events { worker_connections 1024; }

http {

    sendfile on;
    large_client_header_buffers 4 32k;

    upstream service1 {
        server flowableui:8080;
    }
    upstream service2 {
        server angularboite:4200;
    }

    server {
        listen 80;
        server_name www.dzflow.com dzflow.com;

        location / {
            return 301 https://$host$request_uri;
        }
    }

    server {
        listen 80;
        server_name boiteatache;

        location / {
            return 301 https://$host$request_uri;
        }
    }

    server {
        listen 443 ssl;
        server_name www.dzflow.com dzflow.com;

        ssl_certificate /etc/ssl/certs/dzflow.crt;
        ssl_certificate_key /etc/ssl/private/dzflow.key;

        location /flowable-ui {
            proxy_pass         http://service1/flowable-ui;
            proxy_redirect     off;
            proxy_http_version 1.1;
            proxy_cache_bypass $http_upgrade;
            proxy_set_header   Upgrade $http_upgrade;
            proxy_set_header   Connection keep-alive;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
            proxy_set_header   X-Forwarded-Host $server_name;
            proxy_buffer_size           128k;
            proxy_buffers               4 256k;
            proxy_busy_buffers_size     256k;
            log_not_found off;
        }
        location /boite {
            proxy_pass         http://service2/login;
            proxy_redirect     off;
            proxy_http_version 1.1;
            proxy_cache_bypass $http_upgrade;
            proxy_set_header   Upgrade $http_upgrade;
            proxy_set_header   Connection keep-alive;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
            proxy_set_header   X-Forwarded-Host $server_name;
            proxy_buffer_size           128k;
            proxy_buffers               4 256k;
            proxy_busy_buffers_size     256k;
            log_not_found off;
        }
        location = /favicon.ico {
        return 204;
        access_log     off;
        log_not_found  off;
        }
    }    
    
}

my Dockerfile of angular-app:

FROM node:latest as node 
# Set the working directory
WORKDIR /app
# Add the source code to app
COPY . .
# Install all the dependencies
RUN npm install -f

# Expose port 
EXPOSE 4200

ENTRYPOINT ["npm","start"]

nginx Dockerfile :

FROM nginx:latest

COPY nginx.conf /etc/nginx/nginx.conf
COPY dzflow.crt /etc/ssl/certs/dzflow.crt
COPY dzflow.key /etc/ssl/private/dzflow.key

and when i go to check the logs of the container of reverseproxy it gives me this :

 2022/07/07 09:21:45 [error] 22#22: *2 connect() failed (111: Connection refused) while
 connecting to upstream, client: 172.21.0.1, server: www.dzflow.com, request: "GET /boite
 HTTP/1.1", upstream: "http://172.21.0.5:4200/login", host: "localhost"
 172.21.0.1 - - [07/Jul/2022:09:21:45 +0000] "GET /boite HTTP/1.1" 502 559 "-" 
 "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) 
 Chrome/103.0.0.0 Safari/537.36"

please can someone help