Model Name: Mac mini
Model Identifier: Macmini9,1
Chip: Apple M1
Total Number of Cores: 8 (4 performance and 4 efficiency)
Memory: 16 GB

When I press f2 to take a screenshot it freezes. Nothing in the output log. I have to force-quit from activity monitor.
Version: nicephore-fabric-1.18.x-1.2.1.jar
Game Version: 1.18.1 Fabric

Hello ! Have you change anything in the configuration file ?
I just tested with a MacBook Pro M1 and it's working smoothly on my side.
Depending if you enabled it or not, have you opt-in the permission check for the clipboarding feature ?

nicephore.json.zip

Screenshot to clipboard is enabled.