application issue

Hi
I just downloaded MuseScore for the first time. I got the following message though when I tried to open it:

“MuseScore 3” can’t be opened because Apple cannot check it for malicious software."
It said to contact the developer....

I'm on a mac running catalina 10.15.3 (I was on .2 - and then updated to see if that would help but I still get the same message).