Nodal for Big Sur-- malware problem

[manya.curiosum]

Hi, we have issues with Nodal  (2.0.3.1) crashing on Big Sur (11.4).  I now tried to install the newest version (according to this thread which seems to be called 2.1) and it doesn't open. I recall there was a trick to make it open, that is to bypass the warning about malware, but I don't remember what the trick was.  Can someone help?  Thanks, Manya