Trying to login using SSH with a Public Key to USG and only get a password prompt

Using latest version of MacOS and the following ssh version

ssh -V
OpenSSH_8.8p1, OpenSSL 1.1.1l  24 Aug 2021

Run the following to get more info

ssh user@usg -vvv

get a heap of output but the important bit is:

send_pubkey_test: no mutual signature algorithm

The fix

Add the following to your ~/.ssh/config file

Host usg
     HostName 10.197.4.1
     User yourunifsshuser
     IdentityFile ~/.ssh/id_rsa
     PubkeyAcceptedKeyTypes +ssh-rsa

The crucial part is to add the PubkeyAcceptedKeyTypes +ssh-rsa line

The HostName and User values you will need to edit to suit your values.