How to get it

You can find the official documentation here: https://slack.dev/bolt-js/tutorial/getting-started#create-an-app

go to slack API apps and create a new app From an app manifest https://api.slack.com/apps/
Copy and paste the YAML manifest from below:

display_information:
  name: Game Server Watcher
  description: A simple discord/telegram/slack bot that can be hosted on a free service to monitor your game servers and players in style 😎
  background_color: "#440088"
features:
  bot_user:
    display_name: Game Server Watcher
    always_online: false
oauth_config:
  scopes:
    bot:
      - chat:write
      - app_mentions:read
      - channels:history
      - commands
      - reactions:read
settings:
  event_subscriptions:
    bot_events:
      - app_mention
      - message.channels
  interactivity:
    is_enabled: true
  org_deploy_enabled: false
  socket_mode_enabled: true
  token_rotation_enabled: false

Inviting the bot and giving permissions

hit the Install to workspace button

App token

go to Basic Information scroll down to App-Level Tokens and hit the Generate Token and Scopes button to generate an app-level token
give it a name and add the connection:write scope, then hit the Generate button and copy your slack app token

Bot token

go to OAuth and Permissions and copy the Bot User OAuth Token

Environmental variables

Set your app token as the value of the SLACK_APP_TOKEN env var and your bot token as the value of SLACK_BOT_TOKEN env var to enable slack bot features.

GSW Control Panel options

Each server can have multiple channels to post and update the server status message to. The channels are identified by the channel ID.
The simplest way to get a slack channel ID is to right click on the channel name, then go to View channel details and scroll down to the very bottom where you can copy the Channel ID.