如何实现一个自定义询问框

import { promptAction, router } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';

function onBackClick() {
弹出自定义的询问框
  promptAction.showDialog({
您还没有完成支付，确定要返回吗？',
    buttons: [
      {
取消',
        color: '#FF0000'
      },
      {
确认',
        color: '#0099FF'
      }
    ]
  }).then((result:promptAction.ShowDialogSuccessResponse) => {
    if (result.index === 0) {
用户点击了“取消”按钮
      console.info('User canceled the operation.');
    } else if (result.index === 1) {
用户点击了“确认”按钮
      console.info('User confirmed the operation.');
调用router.back()方法，返回上一个页面
      router.back();
    }
  }).catch((err:Error) => {
    let message = (err as BusinessError).message
    let code = (err as BusinessError).code
    console.error(`Invoke showDialog failed, code is ${code}, message is ${message}`);
  })
}