Badour supports sending notifications to various kinds of recipients. Each type has its own documentation page.
Sending a test message
For most recipient types, it's possible to make Badour send a test message to check whether the connection works. After adding a new recipient, click on it in the table of recipients. This brings up the view to edit the recipient. Click "Test" at the bottom left. Wait for a couple of minutes and refresh the page. The recipient should now have a status icon indicating whether the test was successful or not.