The badly named keypair is really the public key of an OpenSSH key pair to be used for access to created servers. You can also create a private key for access to a created server by not passing any argument to the keypair create command.
Compute v2
Create new public or private key for server ssh access
os keypair create
[--public-key <file>]
<name>
Filename for public key to add. If not used, creates a private key.
New public or private key name
Delete public or private key(s)
os keypair delete
<key> [<key> ...]
Name of key(s) to delete (name only)