In Access Profiles, SSH mode access only supports public key file in format ssh-dss or ssh-rsa
See in documentation Create Access Profiles
Public Key File
Specifies the key format, either ssh-dss or ssh-rsa. The product displays this field only when you select the SSH with KeyFile mode.
Does exist plan to support more secure SSH Key like ed25519 ?
Configuration Automation - 12.9.x
Latest version (12.9.0.131 - August 2025) do not support SSH modern algorithms like ed25519
The support of SSH modern algorithms like ed25519 is being worked on by the engineers team for inclusion in a next release of product. ETA date of this is end of 2025