Does this issue relate to a new feature or an existing bug?
Bug
What version of Serilog.Sinks.Elasticsearch is affected?
2.0.3
What is the target framework and operating system?
Net Core 3.1
Please describe the current behavior?
When using minimumLogEventLevel via json based configuration the set value is neither checked nor used. All events are being sent.
a minimal demo of the problem

create empty project
install Serilog
install Serilog.Sinks.Slak

configure something like this:
{
"Name": "Slack",
"Args": {
"WebHookUrl": "https://hooks.slack.com/services/XXXXX",
"CustomChannel": "#errors",
"CustomUserName": "User",
"MinimumLogEventLevel": "Warning",
"BatchSizeLimit": 1,
"ShowExceptionAttachments": true
}
you will find all logs in the channel