Unable to retrieve any value, how should I use GetString() method?

[CaledoniaProject]

Please take a look at this,

package main

import (
	"flag"
	"fmt"
	"log"

	"github.com/0xrawsec/golang-evtx/evtx"
)

func main() {
	flag.Parse()

	for _, filename := range flag.Args() {
		eventFile, err := evtx.OpenDirty(filename)
		if err != nil {
			log.Fatal(err)
		}

		for event := range eventFile.FastEvents() {
			if event.EventID() == 7045 {
				path1 := evtx.Path("/Event/EventData/param1")
				fmt.Println(event.GetString(&path1))
			}
		}
	}
}