Hello Mykrae,
I'm Sravya from Arduino Customer support. To download Matlab supported Arduino Add-ons you will need the latest version of Matlab R2018a. If you have an existing matlab license, please refer to the "chapter 1.3.4 Matlab and Simulink Installations" where you can see all the required products to program the projects in the Arduino Engineering Kit.
Do not hesitate to contact us again at support(at) arduino [dot] cc, if you are unable to download the Add-ons after updating the version.
Best Regards,