After facing this issue for two days i was able to resolve that issue.

solution of this problem is already answered by peoples like do inspect

docker inspect CONTAINER_ID

but while running this command i got a-lot of logs like Host Config Config Network Settings etc. so i got confused which IPAddress to add in the pgAdmin connection because i tried 0.0.0.0 and config, host, networkSettings different -2 IPAddress in the logs but finally it works after trying a-lot.

it works with which IP, we have to add that network ip address (which we created to connect the postgres and pgAdmin.)

like in my case when i run :-

docker inspect postgres_container

 "NetworkSettings": {
        "Bridge": "",
        "SandboxID": "sdffsffsfsfsfsf123232e2r3pru3ouoyoyuosyvo8769696796",
        "HairpinMode": false,
        "LinkLocalIPv6Address": "",
        "LinkLocalIPv6PrefixLen": 0,
        "Ports": {
            "5432/tcp": [
                {
                    "HostIp": "0.0.0.0",
                    "HostPort": "5432"
                }
            ]
        },
        "SandboxKey": "/var/run/docker/231231Ad132",
        "SecondaryIPAddresses": null,
        "SecondaryIPv6Addresses": null,
        "EndpointID": "",
        "Gateway": "",
        "GlobalIPv6Address": "",
        "GlobalIPv6PrefixLen": 0,
        "IPAddress": "",
        "IPPrefixLen": 0,
        "IPv6Gateway": "",
        "MacAddress": "",
        "Networks": {
            "postgres": {
                "IPAMConfig": null,
                "Links": null,
                "Aliases": [
                    "postgres",
                    "0e2j3bn2m42"
                ],
                "NetworkID": "35rhlhl3l53l5hlh3523233k3k4k22l3hk2k4",
                "EndpointID":"b3424n43k52o2i4n235k1k4l2l4hj234f14n2",
                "Gateway": "192.168.16.1",
                "IPAddress": "192.168.16.2",
                "IPPrefixLen": 20,
                "IPv6Gateway": "",

so we have to add the NetworkSettings -> Network -> Postgres(mine created network) -> IPAddress i.e. “IPAddress”: “192.168.16.2”.

After adding this ip it will work.

I hope it will help.