connecting pgadmin container to postgres container

i have created 2 containers [pgadmin4 , postgres ] using below docker compose file.

services:
  db:
    container_name: db
    image: postgres
    environment:
      POSTGRES_USER: ashish
      POSTGRES_PASSWORD: ashish
      PGDATA: /data/postgres
      POSTGRESS_DB: jobapp
    ports:
      - "5432:5432"
    networks:
      - postgres
    restart: always
  pgadmin:
    container_name: pgadmin4
    image: dpage/pgadmin4
    environment:
      PGADMIN_DEFAULT_EMAIL: [email protected]
      PGADMIN_DEFAULT_PASSWORD: root
    ports:
      - "5050:80"  
    networks:
      - postgres
    restart: always

networks:
  postgres:
      name: postgres
      driver: bridge
      

1. for both containers, i am using same bridge network namely postgres.
2. i checked ping status as below to ensure the communication ok.

I logged in pgadmin4 over localhost:5050. then i tried creating a server using the credentials passed in compose file.here the address is passed as network name which is 'postgres'

with above values, getting error as Name not reloved. then i tried address as 'localhost' and '0.0.0.0' as well but still it failed with error message as connection refused.

NETWORK ID     NAME         DRIVER    SCOPE
1d1c44a0b064   bridge       bridge    local
0e0a1145cf91   host         host      local
06fa74116375   my-network   bridge    local
7e93df1725d9   none         null      local
2a74ae7944da   postgres     bridge    local

above is the response of docker network ls.

cat /data/postgres/pg_hba.conf from db container is resulting into below table.

thanks in advance for your valuable time. any attention is highly appreciated.