change vendor public ssh key for sftp

In V7R3, vendor we connect to has changed their public key.

This was set up years ago and only instructions are

https://www.ibm.com/support/pages/configuring-ibm-i-ssh-sftp-and-scp-clients
-use-public-key-authentication



I connected in QP2TERM

ssh -T myprofile@xxxxxxxxxxxx <mailto:bunosftp@xxxxxxxxxxxxx> - was in
original instructions



connected but gave warning - accepted with "yes"

was expecting it might prompt to replace the key..

Message "shell request failed"



With google I have only found initial setup info.

What are the steps to replace the vendor's key.

If it matters, we only connect to them, they never initiate connect to us.



Jim