The recommended version for 2019.2 is 8.3.8. I don't believe you could use an older version of Vuforia as when you enable the Augmented reality checkbox from Player Settings, Unity will automatically install the latest available Vuforia package via Package Manager.
Hi,
The recommended version for 2019.2 is 8.3.8. I don't believe you could use an older version of Vuforia as when you enable the Augmented reality checkbox from Player Settings, Unity will automatically install the latest available Vuforia package via Package Manager.
Thank you.
Vuforia Engine Support