django template checkbox checked

package main

import (
    "html/template"
    "net/http"
)

// Data struct for template data
type Data struct {
    CheckboxValue bool
}

// Handler function to render the template
func handler(w http.ResponseWriter, r *http.Request) {
    tmpl, err := template.New("index.html").Parse(`
<!DOCTYPE html>
<html>
<head>
    <title>Checkbox Example</title>
</head>
<body>
    <form action="/submit" method="post">
        <label for="checkbox">Check me:</label>
        <input type="checkbox" id="checkbox" name="checkbox" {{if .CheckboxValue}}checked{{end}}>
        <input type="submit" value="Submit">
    </form>
</body>
</html>
`)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }

    data := Data{CheckboxValue: true}

    err = tmpl.Execute(w, data)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
    }
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}