You can use install it via NPM:
$ npm install gitbook-plugin-clicky
And use it for your book in the book.json:
{
"plugins": ["clicky"]
}
You can set the clicky Site ID ID using the plugins configuration in the book.json:
{
"plugins": ["clicky"],
"pluginsConfig": {
"clicky": {
"site_id": "XYXYXY"
}
}
}