JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="chkAllAccounts" value="check1" >This is a tickbox<br>
<select name="lstClients">
    <option value"value1">Value 1</option>
    <option value"value1">Value 1</option>
    <option value"value1">Value 1</option>
    <option value"value1">Value 1</option>
</select>

JavaScript

$('input[name=chkAllAccounts]').change(function() {
    if ($(this).is(':checked')) {
        $('select[name=lstClients]').prop('disabled', false );
    } else {
        $('select[name=lstClients]').prop('disabled','disabled' );
    }
});