Questions about unity errors.

[aaaqw]

I am using unity2021.3.16f1, imported Eye and Facial Tracking SDK 1.3.6.8 and wrote scripts. However, I get the following error in "using SRanipal;".

「Assets\アイトラッキング\EyeTrackingDataLogger.cs(3,7): error CS0246: The type or namespace name 'SRanipal' could not be found (are you missing a using directive or an assembly reference?)」

Does this mean that unity2021.3.16f1 and Eye and Facial Tracking SDK 1.3.6.8 are incompatible? Also, what version of the Eye and Facial Tracking SDK is compatible with unity2021.3.16f1?