Screenshot webpages as PNG with GoLang

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "net/http"
    "os"
    "time"
)

func main() {
    request := map[string]any{
        "url": "https://example.com",
        "format": "png",
        "viewport_height": 630,
        "viewport_width": 1200,
    }

    body, err := json.Marshal(request)
    if err != nil {
        panic(err)
    }
    httpRequest, err := http.NewRequest(http.MethodPost, "https://hcti.io/v1/image", bytes.NewReader(body))
    if err != nil {
        panic(err)
    }
    httpRequest.SetBasicAuth(os.Getenv("HCTI_API_ID"), os.Getenv("HCTI_API_KEY"))
    httpRequest.Header.Set("Content-Type", "application/json")

    client := &http.Client{Timeout: 30 * time.Second}
    response, err := client.Do(httpRequest)
    if err != nil {
        panic(err)
    }
    defer response.Body.Close()
    responseBody, err := io.ReadAll(response.Body)
    if err != nil {
        panic(err)
    }
    if response.StatusCode >= http.StatusBadRequest {
        panic(fmt.Sprintf("HCTI request failed (%d): %s", response.StatusCode, responseBody))
    }

    var result struct {
        URL string `json:"url"`
    }
    if err := json.Unmarshal(responseBody, &result); err != nil {
        panic(err)
    }
    fmt.Println(result.URL)
}