Applications for the HTC VIVE Focus 3 VR headset can be found in the VIVE Business AppStore
Installing PeriopSim VR for HTC VIVE Focus 3 via the HTC Business AppStore
PeriopSim VR is a free application and the recommended method of accessing the application is through accessing the HTC Business AppStore via web browser:
https://business.vive.com/us/support/focus3/category_howto/getting-apps-from-the-appstore.html
Access to the Business Store will require a free HTC account unless your organization has already established an HTC organizational account.
PeriopSim VR is located at:
https://business.vive.com/appstore/detail/7609fdb7-41e5-4f10-bd00-b199ed9b1f66
After the application has been selected and enabled in the Business Store you have to add it to each VR headset you intend to use. The instructions are at the bottom of the Getting Apps page or located here https://business.vive.com/us/support/focus3/category_howto/downloading-vr-titles.html#downloading-vr-titles
See the VR Troubleshooting guide if any issues are found during this process or contact support@periopsim.com.