Hello @Ajaychethi ,

As per your requirement, created Custom type Variable and added UI Macro into that..

Before Check :

After Checked :

UI Macro script :

<?xml version="1.0" encoding="utf-8" ?>
<j:jelly trim="false" xmlns:j="jelly:core" xmlns:g="glide" xmlns:j2="null" xmlns:g2="null">

    <input type="checkbox"
           name="${jvar_name}"
           id="${jvar_name}"
           onchange="
               g_form.setValue('${jvar_name}', this.checked ? 'true' : 'false');
               document.getElementById('${jvar_name}_label').style.fontWeight =
               this.checked ? 'bold' : 'normal';
           " />

    <label id="${jvar_name}_label" for="${jvar_name}">
        Bold Variable
    </label>

</j:jelly>

If my response helped mark as helpful and accept the solution.