Botão fixo CSS
<style>
.footer {
position: fixed;
left: 0;
bottom: 0;
width: 100%;
color: white;
text-align: center;
}
</style>
<footer class="footer mt-auto py-3 bg-light">
<div class="container">
<span class="text-muted">Place sticky footer content here.</span>
</div>
</footer>
Tiago F2