This is NLog target for Slack, check following configuration:
<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" autoReload="true">
<extensions>
<add assembly="NLog.SlackTarget"/>
</extensions>
<targets async="true">
<target name="Slack" xsi:type="Slack"
webhookUrl="https://hooks.slack.com/services/xxx/yyy/zzz"
layout="${message}" />
</targets>
<rules>
<logger name="*" minlevel="Debug" writeTo="Slack" />
</rules>
</nlog>