An Alkan Air Dornier Do-228, registration C-FUCN performing a flight from Dawson City,YT to Whitehorse,YT (Canada) with 2 crew, was on approach to Whitehorse’s runway 14R when the crew did not receive indication the nose gear had extended. The crew performed a low approach which confirmed the nose gear was not extended. The aircraft positioned for another approach to runway 14R and nose gear up landing, and landed without nose gear about 20 minutes after the low approach.