for-each-btn
HTML
<div id="accordion">
<!-- repeated content \/ -->
<div class="card">
<div class="card-header headingThree">
<h5 class="mb-0 d-flex">
<div class="billing">
<input type="checkbox" class="billing-checkbox" checked>
<button class="btn btn-info text-white collapsed d-flex align-center" data-toggle="collapse" data-target="#<%= turma.nome %>" aria-expanded="false" aria-controls="turma.nome" id="btn">
turma.nome
</button>
</div>
</h5>
</div>
</div>
<!-- repeated content /\ -->
<div class="card">
<div class="card-header headingThree">
<h5 class="mb-0 d-flex">
<div class="billing">
<input type="checkbox" class="billing-checkbox" checked>
<button class="btn btn-info text-white collapsed d-flex align-center" data-toggle="collapse" data-target="#<%= turma.nome %>" aria-expanded="false" aria-controls="turma.nome" id="btn">
turma.nome
</button>
</div>
</h5>
</div>
</div>
<div class="card">
<div class="card-header headingThree">
<h5 class="mb-0 d-flex">
<div class="billing">
<input type="checkbox" class="billing-checkbox" checked>
<button class="btn btn-info text-white collapsed d-flex align-center" data-toggle="collapse" data-target="#<%= turma.nome %>" aria-expanded="false" aria-controls="turma.nome" id="btn">
turma.nome
</button>
</div>
</h5>
</div>
</div>
<div class="card">
<div class="card-header headingThree">
<h5 class="mb-0 d-flex">
<div class="billing">
<input type="checkbox" class="billing-checkbox" checked>
<button class="btn btn-info text-white collapsed d-flex align-center" data-toggle="collapse" data-target="#<%= turma.nome %>" aria-expanded="false" aria-controls="turma.nome" id="btn">
turma.nome
</button>
</div>
</h5>
</div>
</div>
</div>
JavaScript
jQuery($ => {
$('.billing-checkbox').on('change', e => {
$(e.target).next('button').prop('disabled', !e.checked);
});
});