better-scroll提示document.queryselector不是函数怎么解决

// 组件创建完后调用
mounted () { // mounted生命周期创建之后
this.scroll = new BScroll(document.queryselector('.wrapper'),{
probeType: 3,
pullupload: true
})
this.scroll.on('scroll', (position) => {
console.log(position);
})
}

better-scroll 装的2.0版本的，报错：

vue.runtime.esm.js?c320:619

   [Vue warn]: Error in mounted hook: "TypeError: document.queryselector is not a function"

found in

at src/views/category/Category.vue
at src/App.vue

他说我document.queryselector有问题，请问这里该怎么写？

是document.querySelector，注意大小写