SLACK_WEBHOOK_URL - which is the URL for the Slack installed application that is available when the integration app is installed to the kudos channel (already done). This is on the Installed App Settings tab.
SLACK_BOT_TOKEN - this is available on the same tab. This part allows the application to search for a channel id and user ids.
This requires two environment variables:
https://api.slack.com/apps/A081ESV0D5W/install-on-team
The application has already been installed to the #kudos channel. We just need to deploy this and provide the above environment variables.
This is what the test channel looks like: