How can an SSH key be deleted and SSH key logging be disabled?

[jefazo92]

I want to disable SSH Key logging completely. Also I have an ssh key configured in my Fortigate but I am unable to delete it. I have tried using delete, unset and setting the SSH key as an empty key but the key does not get deleted. How may I delete my key and disable SSH key logging completely?

[dbhavsar]

Good day @jefazo92 ,

I believe you can enable admin-ssh-password under global settings then try again logging in with key. 

Reference: https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-limit-the-authentication-mechanism-... 

Or you can edit the admin via cli and
config system admin
edit <admin-username>
unset set ssh-public-key1/2/3
next
end