JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
    <div class="inner">
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
        <div class="item">Item</div>
    </div>
</div>

CSS

.outer {
    border: 1px solid black;
    height: 200px;
    overflow-y: scroll;
    width: 300px;
}

.inner {}

.item {
    background: grey;
    border: 1px solid red;
    height: 50px;
}