Uknown feed format
Luigi's Box onboarding currently accepts only feeds in an XML format. If you see an error regarding unknown feed formats, it probably means you have entered a URL that is not a valid XML.
How to resolve this issue
First, check if the feed is in XML format. You need to find the location of your XML file, which should be easy with any website solution you use. If you’re having trouble, use an internet search to find out where you can locate your XML file.
The feed's URL most frequently ends with .xml. If you see any other extension, the feed is probably not in XML format.
The second solution is to check if the feed is not IP address restricted. If it is, you will need to make it public or contact support@luigisbox.com to request a static IP routing.