JSFiddle - React, Tailwind, and code Playground

HTML

<p class="line"><span>[extra_menu menu_name='Footer' menu_type='horizontal' ]</span></p>

CSS

.line {
  line-height: 0.5;
  text-align: center;
}
.line span {
  display: inline-block;
  position: relative;  
}
.line span:before
{
  content: "";
  position: absolute;
  height: 15px;
  border-bottom: 1px solid red;
  top: 0;
  width: 600px;
}
.line span:before {
  right: 100%;
  margin-right: 15px;
}