JSFiddle - React, Tailwind, and code Playground

HTML

<svg width="100" height="100">
   <line x1="0" y1="40" x2="200" y2="40" style="stroke:rgb(255,0,0);stroke-width:20"/>
   Sorry, your browser does not support inline SVG.
</svg>

JavaScript

const line = document.querySelector("svg line");
console.log(line)

console.log(line.getBBox({"stroke": true}))