JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
<li>a</li>
<li>b</li>
<li>c</li>
<li>d</li>
<li>e</li>
<li>f</li>
</ul>

CSS

ul {
  display: flex;               /* establish flex container */
  flex-direction: column;      /* align children vertically */
  justify-content: flex-end;   /* align children at container bottom */
  border: 1px solid red;
  height: 80px;
  overflow-y: scroll;
}