Slack

Slack use Incoming Webhooks whose constructs typically support both text and block rich text, and can be configured as follows:

Text format

{
  "text": "#{@title}\nPlatform: #{@device_type}\nUpload at: #{@uploaded_at}"
}

Block rich text format

A simple block with markdown support

{
  "blocks": [
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "## #{@title}\nPlatform: #{@device_type}\nUpload at: #{@uploaded_at}\nInstal QRcode:\n![qrcode](#{@qrcode_url})"
      }
    }
  ]
}

Better look at some of the structures shown in the block

{
  "blocks": [
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": @title,
      }
    },
    {
      "type": "section",
      "fields": [
        {
          "type": "mrkdwn",
          "text": "*Platform:*\n#{@device_type}"
        },
        {
          "type": "mrkdwn",
          "text": "*Upload at:*\n#{@uploaded_at}"
        }
      ]
    },
    "accessory": {
      "type": "image",
      "image_url": @qrcode_url,
      "alt_text": "install qrcode"
    }
  ]
}