Check the below link..
You need to issue 'feature ssh' to enable this and rest is same as IOS.
I do not have 9300 to test but here is what I suggest (basic steps)...
1. Assign host name to the switch
2. Create local admin with password
2. feature ssh
3. Crypto key generate rsa modulus 2048 (if that does not work try what listed in doc -ssh key rsa 2048)
Test ssh access from management workstation (make sure management workstation able to reach switch).
configure it as below
ssh key rsa 2048 force
username admin password yorupassword role network-admin
now when you ssh issue
type yes for certificate
and then enter the password
192.168.1.1 represent the nexus ip address that you trying to access
please rate if helpfull