Twinbuild for HoloLens is a free download from the Microsoft Windows Store.
Note that trial licenses of Twinbuild Pro are offered on a per-device basis. If you need a second trial for your device please contact support. After installing Twinbuild you can launch the app by looking at any model Link on your HoloLens.
Scan the QR Code above with your HoloLens 2 to display an App Launch button (a green rectangle with a large Play icon). Tap the App Launch button and confirm any prompts to open the Windows Store page for Twinbuild. Sign in to your Windows Store account if needed, then tap Get to install Twinbuild on the HoloLens 2. If you can’t scan the QR code, visit this page on the HoloLens 2 and tap the button below.