Hello MetalB, thank you very much for your answer.
I started this morning with either the ITCH application, and with Safari connected on the game page :

- With Safari : OK today. As shown in this screenshot, this morning after starting the Mac I have MacOS in the name downloading (see the red circle), where I had Linux yesterday, so perhaps a bug in Safari.

- With ITCH application : bad link. As shown in the screenshot below, in the red circle one can see Linux in the download name, when clicking on any of the 4 "Download" buttons. 

SO I will be able to try the MacOS version downloaded with Safari.
Thanks