If you want to use UINotify plugin with KillRecords and have the icon work as well you'll also need ImageLibrary plugin on your server. After that setup the UINotify plugin as you want with KillRecords own message section so only it uses that specific message. Edit the KillRecords config to use the ID for that message and enable. In the UINotify config you can enable the image and copy this address for the image: http://www.skilledsoldiers.net/Rust/killrecords80.png
In UINotify for that message use these settings:
"Title Key (lang)": "Kill Records",
"Image Settings": {
"Enabled": true,
"Image": "http://www.skilledsoldiers.net/Rust/killrecords80.png",