Hi @siqiyaoyao and thanks for your query. Unfortunately, the XR SDK is significantly different from the Tobii Pro SDK Unity Bindings with several distinctions including syntax and methods.
Accordingly, conversion from projects written in the Pro SDK to XR SDK will require some manual editing I am afraid for which we do not currently have any official guide. We would recommend that you have a look at the included XR samples to get an idea of how the basic operations work and try to work backwards.
If it’s possible to share your project on github or similar, we can take a further look and perhaps offer some suggestions.
In addition, pupil size is not exposed in the XR SDK either, this is exclusive to the Pro SDK for the time being.