Sketchup restarted, not sure why only roundcorner is showing in extension manager, both plugins have been installed correctly

Hi
Is anyone facing issue installing Roundcorner on S-Up 2021 for Mac.
LibFredo6 installed but not showing in extension manager, roundcorner installed and enabled in extension manager but not working. Tool pallet is not coming up.
Can anyone please help

Thanks
Agata