Create a bot with the BotFather command: /newbot, name, username, and grep the API token from the message.
Invite the bot into a group.
Run the BotFather command: /setjoingroups to disable the bot from joining groups.

Now, the bot will only answer group members.

Inside the group, type: /hello.
Run curl https://api.telegram.org/bot<token>/getUpdates | jq to get and store the chat ID.
export TGBWP_TOKEN=Enable debug:export debug. DEBUG=true`

Build with: go build -buildmode=plugin -o ~/.local/share/tgbwp/plugins/ip.so ./plugins/ip

Configuration

Example configuration, replace <number> with the current chat numbers:

{
  “id”: {
    “user”: {
      “knackwurstking”: <number>
    },
    “chat”: {
      “alice”: <number>
    }
  }
}