Copy your CallRail API secret token to your Housecall Pro account.
In your CallRail account, select "Settings" in the top navigation, then scroll to the bottom to find the "Webhooks" App.
In the app page, scroll to the bottom and open advanced configurations. In there you will find a webhook signature secret token. Copy that to your clipboard.
Back in Housecall on the CallRail app page, paste that token into the indicated field.
Copy Housecall Pro webhook URL into CallRail
After pasting your webhook secret token into Housecall Pro, you will be given a URL. Copy that to your dashboard.
Paste that token into the Pre-Call webhook option on the webhook app details page.
Update your app and make sure the app is enabled. With notifications enabled, you will start to see desktop notifications coming through when receiving calls on your CallRail number.