How do I install 2018a or 2018b version of MATLAB with a new student suite license?

I want to use SIMULINK with RT-Lab for a project of mine and want to purchase a student suite license for that purpose, but RT-Lab version i have is only compatible with 2018 version or older for Matlab/simulink.

I want to ask is it possble to download older versions with a student suite license? If yes how can i do it? Note that i need matlab, simulink along with matlab code and simulink coder to run it with rt-lab.

Thank you for your help in advance.