The all Messenger versions ( as any other products ) are available in Download area of module (see my screenshorts). The latest version which is compatible with UNA 12 is Messenger 12.0.5.
I understand now, A BIG THANKS for the answer, I didn't see that button.
It was better that when you press the download button, all the versions can be seen directly. without having to open another intermediate page to see all the versions.
I suggest you to remove the intermediate page where only see the latest version is visible. When you click on the download button, a list of all available versions will open.
Or to open several previous versions in the intermediate page, at least three and the button for more should be right below them MORE INTUITVE.
Simpler things are more practical, my self I searched for days without seeing that button.
I apologize for the inconvenience, but I did not expect there to be so many DEPTH pages