Installing Frescobaldi 3.1.3 on Mac with MacOS 12.1

[Michael Hendry]

Dear LilyPond Users,

I unsubscribed from the list during lockdown and the subsequent lack of musical 
opportunities, and in the meantime I’ve got a faster Mac running Monterey.

I downloaded Frescobaldi-3.1.3-x86_64.dmg and installed it, but am prevented 
from running it because ‘“Frescobaldi.app” cannot be opened because the 
developer cannot be verified” as being free from malware.

Can anyone advise me:

a) how to resubscribe to the list.
b) how to get round the verification problem.

Regards,

Michael Hendry