Is it possible to view my 360 virtual tour in a virtual reality (VR) headset such as Google Cardboard or Oculus Go?

Yes of course.

With Oculus Go:

Once the headset is on your head, you'll need to go to your internet browser (in VR Google Chrome or Oculus Web Browser) and open the link of the Klapty tour. Oculus Go does not allow copying and pasting text, we recommend to send the link to your email, then open your inbox from the browser in Oculus, then you can just click on the link to open the tour. Once the window of your tour is open, click on the "VR headset" icon on the bottom.

With a smartphone:

Open the tour on your smartphone, then place the smartphone into the headset and click on the "VR headset" icon on the bottom of the tour.
Compatible with Android, iOS, iPhone, Samsung, etc. Use the preferred browsers on your phone for VR mode: Google Chrome or Safari.

Also make sure that your browsers and your phone are up to date with the latest version.