1 Prepare your slack channel to receive exceptions

1 - Lets create a channel and a webhook url to receive exception messages.

1.1 On slack app select add channel > Create a new channel > Set a name, example: "bug-report" or "exceptions" > Confirm

Results:

2 - Install Incoming WebHook App

2.1 Select browse Slack > Apps > Find "Incoming Webhooks" > Add

3 - On new tab select add to slack.

3.1 Select your channel to receive exceptions messages from your application > Add Integration

3.2 It's ready! Copy the webhook URL generated.