How to Use db as postgres, using --db-type=postgres not working

uisng cmd
docker compose -p pwd -f pwd.yml up -d

is is by default fetching maridb connection even if I am using --db-type=postgres in bench new site cmd
, please help to connect to postgres

my pwd.yml file

version: "3"

services:
  backend:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: on-failure
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

  configurator:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: none
    entrypoint:
      - bash
      - -c
    # add redis_socketio for backward compatibility
    command:
      - >
        ls -1 apps > sites/apps.txt;
        bench set-config -g db_host $$DB_HOST;
        bench set-config -gp db_port $$DB_PORT;
        bench set-config -g redis_cache "redis://$$REDIS_CACHE";
        bench set-config -g redis_queue "redis://$$REDIS_QUEUE";
        bench set-config -g redis_socketio "redis://$$REDIS_QUEUE";
        bench set-config -gp socketio_port $$SOCKETIO_PORT;
    environment:
      DB_HOST: db
      DB_PORT: "5432"
      REDIS_CACHE: redis-cache:6379
      REDIS_QUEUE: redis-queue:6379
      SOCKETIO_PORT: "9000"
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

  create-site:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: none
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs
    entrypoint:
      - bash
      - -c
    command:
      - >
        wait-for-it -t 120 db:5432;
        wait-for-it -t 120 redis-cache:6379;
        wait-for-it -t 120 redis-queue:6379;
        export start=`date +%s`;
        until [[ -n `grep -hs ^ sites/common_site_config.json | jq -r ".db_host // empty"` ]] && \
          [[ -n `grep -hs ^ sites/common_site_config.json | jq -r ".redis_cache // empty"` ]] && \
          [[ -n `grep -hs ^ sites/common_site_config.json | jq -r ".redis_queue // empty"` ]];
        do
          echo "Waiting for sites/common_site_config.json to be created";
          sleep 5;
          if (( `date +%s`-start > 120 )); then
            echo "could not find sites/common_site_config.json with required keys";
            exit 1
          fi
        done;
        echo "sites/common_site_config.json found";
        bench new-site --force --db-type=postgres --db-host=db --admin-password=admin --db-root-password=admin --install-app frappe --set-default frontend;

  db:
    image: postgres:15
    healthcheck:
      test: pg_isready -h localhost -U postgres
      interval: 1s
      retries: 15
    deploy:
      restart_policy:
        condition: on-failure
    environment:
      POSTGRES_PASSWORD: 1234
    volumes:
      - db-data:/var/lib/postgresql/data


  frontend:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    depends_on:
      - websocket
    deploy:
      restart_policy:
        condition: on-failure
    command:
      - nginx-entrypoint.sh
    environment:
      BACKEND: backend:8000
      FRAPPE_SITE_NAME_HEADER: frontend
      SOCKETIO: websocket:9000
      UPSTREAM_REAL_IP_ADDRESS: 127.0.0.1
      UPSTREAM_REAL_IP_HEADER: X-Forwarded-For
      UPSTREAM_REAL_IP_RECURSIVE: "off"
      PROXY_READ_TIMEOUT: 120
      CLIENT_MAX_BODY_SIZE: 50m
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs
    ports:
      - "8080:8080"

  queue-long:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: on-failure
    command:
      - bench
      - worker
      - --queue
      - long,default,short
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

  queue-short:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: on-failure
    command:
      - bench
      - worker
      - --queue
      - short,default
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

  redis-queue:
    image: redis:6.2-alpine
    deploy:
      restart_policy:
        condition: on-failure
    volumes:
      - redis-queue-data:/data

  redis-cache:
    image: redis:6.2-alpine
    deploy:
      restart_policy:
        condition: on-failure
    volumes:
      - redis-cache-data:/data

  scheduler:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: on-failure
    command:
      - bench
      - schedule
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

  websocket:
    image: ghcr.io/dehaat/frappe/frappe:1.0.0
    deploy:
      restart_policy:
        condition: on-failure
    command:
      - node
      - /home/frappe/frappe-bench/apps/frappe/socketio.js
    volumes:
      - sites:/home/frappe/frappe-bench/sites
      - logs:/home/frappe/frappe-bench/logs

volumes:
  db-data:
  redis-queue-data:
  redis-cache-data:
  sites:
  logs:

No need to install frappe. It is installed when site is created.

so, need to remove complete text from command?

also its not solving the issue of connecting to postgres i.e trying to fetch from mariadb only, how can we fix that?

logs

2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/query_builder/utils.py", line 84, in execute_query
2024-05-22 17:23:58     result = frappe.db.sql(query, params, *args, **kwargs)  # nosemgrep
2024-05-22 17:23:58              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/database/database.py", line 213, in sql
2024-05-22 17:23:58     self.connect()
2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/database/database.py", line 118, in connect
2024-05-22 17:23:58     self._conn: "MariadbConnection" | "PostgresConnection" = self.get_connection()
2024-05-22 17:23:58                                                              ^^^^^^^^^^^^^^^^^^^^^
2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/database/mariadb/database.py", line 107, in get_connection
2024-05-22 17:23:58     conn = self._get_connection()
2024-05-22 17:23:58            ^^^^^^^^^^^^^^^^^^^^^^
2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/database/mariadb/database.py", line 113, in _get_connection
2024-05-22 17:23:58     return self.create_connection()
2024-05-22 17:23:58            ^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-22 17:23:58   File "/home/frappe/frappe-bench/apps/frappe/frappe/database/mariadb/database.py", line 116, in create_connection
2024-05-22 17:23:58     return pymysql.connect(**self.get_connection_settings())