JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" value="check" id="AutoCalculateMandate" onchange = "AutoCalculateMandateOnChange(this)"/>
<label for="AutoCalculateMandate">
    Auto Calculate
</label> <br />

<input type="text" id="LevyFee" class="form-control" data-required="true" ">

JavaScript

function AutoCalculateMandateOnChange(element){
    element.checked ? document.getElementById("LevyFee").disabled = true : document.getElementById("LevyFee").disabled = false;    
}