How to use HTTPCanary PacketsUpload Plugin?

Question

Don't understand to use HTTPCanary PacketsUpload config.json

Here is what config.json contain

{
"header1":"value1",
"header2":"value2",
"header3":"value3",
"server":"url"
}

1. What should I change on config.json?
2. In my server, what should I prepare?

Thank you.