@Dmitry Maslennikov - I did check and if you are a licensed customer you can download 2021.2 InterSystems IRIS For Health CE from the WRC Software Distributions page: https://wrc.intersystems.com/wrc/coDistCD.csp
But I'll still push to figure out why it's missing from containers.InterSystems.com ....

Great news Mike!  Thanks for your work to make our Preview Software more widely available :)

As a further point on this topic, Customers can continue to get Preview Kits via the WRC Downloads if they wish to do it as they have in the past.  This enhancement to Evaluation now makes it possible for the first time for Prospects to access our Preview kits.  

@Yuri Marx - there is one thing that I don't see on this list (probably because it is a newer resource), but should probably be the first thing listed in the article:

https://gettingstarted.intersystems.com/

InterSystems IRIS Sandbox with browser-based IDE for walking through guided tutorials on a number of topics.  If someone wants to be hands-on in minutes and ramp up their learning from there, this is probably the place to start!!

avoid loading anything into %SYS unless it is a class / routine that starts with a "z" ... everything else will be overwritten when you upgrade InterSystems IRIS.  If you ever want to class to be available to all namespaces, you can call it %z<some name> and load it into %SYS and then you can call it from all namespaces and it should survive an upgrade.

Let us know if you got it working!

if you import this class into IRIS you will then be able to run the methods.  Look up the docs for $system.OBJ.Load() .. you will load and compile the class and the. you can call the methods like this:

Do ##class(User.Ready.ConvertCSV).ConvertN()

(I assume you cut out the actual logic of the methods when you pastes it above as what you pasted is incomplete)