JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="1" class="btn" onclick="reply_click(this.id)">info</a>

<form>
    
    <input type="text" id="product_name" />
    
</form>

<script type="text/javascript">
    
    function reply_click(clicked_id)
    {
        if(clicked_id == "1")
        {
            document.getElementById('product_name').value = 'Soap';
        }
    }    
    
</script>