Hi @leppster13, and thanks for your query. There are a number of ways to enable eye tracking between scenes.
One way is to have the TobiiXR_Initializer prefab in the start scene and make it DontDestroyOnLoad, another way is to have one initializer per scene. You can also make either of these setups work dynamically in code. If you could kindly clarify what you are trying to achieve we will be better placed to assist you further. Best Wishes