Step 1: Login to your Datto Appliance and click "Create API Key"
Step 2: Name the key and select "Backup Radar" under Access Controls
Step 3: Copy the Public and Private Key. You can find this under Admin > Integrations.
Step 4: Once you have the Rest API keys login to Backup Radar. Turn on the Enabled Button, Turn on Rest API, Input a Name for your integration (this can be anything you want), then Paste in the Public and Secret (Private) key as shown below and click Save.