Man pages matching name ssh-add in section 1:

ssh-add.1.en	debian 10 / openssh-client
ssh-add.1.de	debian 11 / manpages-de
ssh-add.1.en	debian 11 / openssh-client
ssh-add.1.de	debian 12 / manpages-de
ssh-add.1.en	debian 12 / openssh-client