JSFiddle - React, Tailwind, and code Playground

HTML

<span class="input-euro left">
    <input type="text" />
</span>
<br/>
<span class="input-euro right">
    <input type="text" />
</span>

CSS

.input-euro {
     position: relative;
 }
 .input-euro.left input {
     padding-left:18px;
 }
 .input-euro.right input {
     padding-right:18px;
     text-align:end; 
 }


 .input-euro:before {
     position: absolute;
     top: 0;
     content:"€";
 }
 .input-euro.left:before {
     left: 5px;
 }
 .input-euro.right:before {
     right: 5px;
 }