main.go

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
)

var url = "https://ipv4ip.com/?format=json"

type Address struct {
	Ip string `json:"ip"`
}

func main() {
	resp, err := http.Get(url)
	if err != nil {
		fmt.Println("No response from request")
	}
	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	var jsonstr = body
	var getIp Address
	json.Unmarshal([]byte(jsonstr), &getIp)
	if err != nil {
		panic(err)
	}
	fmt.Println(getIp.Ip)
}