Whomever is maintaining the Calckey ynh installation, the software writers have renamed and rebranded Calckey to FireFish. They still have the link to the yunohost app on that page but the yhn app doesn’t exist because it’s still called Calckey by ynh.
@oufmilo and I (maintaining the package) are working on it, but don’t expect the change to happen soon: 1) it’s a bunch of work 2) it’s not stabilized on Calckey-Firefish side (they changed the repository twice today).
People willing to try most of the new features are able to do so by using the v14 release candidate 3 available in Calckey(_ynh) testing branch GitHub - YunoHost-Apps/calckey_ynh at testing
It should be working well, but that’s not 100% guaranteed.