NavCanada turned off all VOR receiver test facilities (VOT) in Canada (I believe).
This means there is no longer a way for you to test your VOR on the ground before you depart.
I’ve never used one before, and I suspect most people nowadays don’t use them either.
The full list of VOTs that are decommissioned can be found at NavCanada.
VOTs were handy in that you could determine the error rate of your VOR receiver on the ground. For example, you’d tune up the VOT frequency and turn the OBS to 180°. You should see the “to” flag with the needle centred. If not, then you know how many “dots” your VOR is off by. Similarly, you can also tune the receiver to 000° and see a “from” flag.
Are VOTs still used elsewhere in the world?