Farmbeats requests require a resource like Farm, Device, Sensor etc along with a HTTP method like GET, POST, DELETE etc. The error message is indicating that the resource is missing. You can append a farmbeats resource like farm, device, sensor to get appropriate resources.
Alternate way of doing the same would be to go to swagger endpoint. Here's a swagger link for your service - https://farmbeatsdatahub.azurewebsites.net/swagger/index.html.
Let us know if that helps