The renew credentials action can be invoked via the Credential menu or by pressing Ctrl + R. Additionally, if Monitor credentials expiration option is enabled for all identities or for a specific identity, then those credentials will be automatically renewed before they expire.
An identity must be selected before invoking the renew credentials action.
Not all credentials can be renewed. The actual logic of renewing the credentials is up to each credentials provider. In general NetIDMgr will invoke each credentials provider to renew their respective credentials. For Kerberos 5, if the initial ticket is renewable and not expired, then it will obtain a renewed initial ticket. For Kerberos 4, once a renewed Kerberos 5 initial ticket is obtained, it will try to use a Krb524 translator to obtain a new Kerberos 4 initial ticket.