Connect golang application to payment gateway

test-payment.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
)

// https://aqayepardakht.ir/api/
func main() {
	http.HandleFunc("/payment", func(w http.ResponseWriter, r *http.Request) {
		var data map[string]string
		body, _ := json.Marshal(map[string]any{
			"pin":      "sandbox",
			"amount":   20000,
			"callback": "http://localhost:8000/callback",
		})
		res, _ := http.Post("https://panel.aqayepardakht.ir/api/v2/create", "application/json", bytes.NewReader(body))
		json.NewDecoder(res.Body).Decode(&data)
		fmt.Fprintf(w, "https://panel.aqayepardakht.ir/startpay/sandbox/%s", data["transid"])
	})
	http.HandleFunc("/callback", func(w http.ResponseWriter, r *http.Request) {
		r.ParseForm()
		fmt.Fprintf(w, "status: %s; 1 for success", r.PostFormValue("status"))
	})
	http.HandleFunc("/verify", func(w http.ResponseWriter, r *http.Request) {
		var data map[string]string
		body, _ := json.Marshal(map[string]any{
			"pin":     "sandbox",
			"transid": r.URL.Query().Get("transid"),
			"amount":  20000,
		})
		res, _ := http.Post("https://panel.aqayepardakht.ir/api/v2/verify", "application/json", bytes.NewReader(body))
		json.NewDecoder(res.Body).Decode(&data)
		fmt.Fprintf(w, "status code: %s; 2 for verified", data["code"])
	})
	http.ListenAndServe(":8000", nil)
}