XPForce will send Force Feedback commands to any joystick that Windows recognises as supporting forces. You don't necessarily need customised drivers to do this - for example, the old Microsoft Sidewinder Force Feedback 2 works happily on Windows 8.1 and newer despite only using Windows' built-in drivers. 

If your joystick doesn't have motors built in to provide force feedback, there's no way that XPForce can send them any commands! Please check before buying that it's compatible with your joystick, and that your joystick does in fact have force feedback capability.

Some sticks do seem to need "official" drivers rather than the standard Windows ones. Even if it works just fine as a standard controller, the force aspect might not work if the drivers are incorrect.  Check that your stick is fully supported by running "dxdiag" - you should already have it installed as part of DirectX. Click on the "Save All Information" button and it will create a text file. If you open that file, under the section for your joystick there should be several entries like this:

FF Driver: C:\Windows\System32\pid.dll
FF Driver Date: 10/30/2015 07:18:09
FF Driver Version: 10.00.10586.0000
FF Driver Size: 45568 bytes
 

If it says "FF Driver: n/a" then there's definitely no force driver installed, so please visit the manufacturer's website and try to find the correct drivers.

You can also try the "DirectX Force Test Program", available for free from https://www.fsmissioneditor.com/downloads/ . This will let you simply select a controller and send individual commands to it. If your stick shows forces in the test program but not in X-Plane then please get in touch. If the Force Test program also doesn't list your controller, or the forces don't work, then it's either a driver or a hardware problem.

Finally of course, you can try using any other force-enabled game you have.