ASUS Transformer Pads are available with Windows RT, Windows 8 or Android (https://www.asus.com/us/Tablets_Mobile/Transformer_Pad_Products/). Flash Player is available for, and works with Windows RT and Windows 8, so I'd have to assume that you have an Android Transformer Pad, which the TF300T is (https://www.asus.com/us/Tablets_Mobile/ASUS_Transformer_Pad_TF300T/). Android no longer supports Flash Player (for almost a year and a half now).
See: "Why can't I install Flash Player on my Tablet?" (Kindle or Samsung Galaxy) which lists specifically Galaxy and Kindle, but applies to ALL Android devices, and the support was dropped by the developer of the OS and not necessarily by the individual manufacturers of devices that run Android.