If you are trying to add buttons that stick to the bottom of a mobile device, below are some code snippets you can use.
Contact Button only
<div id="footer-contact" class="container">
<div class="row">
<div class="col-12"><a href="/contact" class="btn btn-block btn-primary">Contact</a></div>
</div>
</div>
Contact & Call button
<div id="footer-contact" class="container">
<div class="row">
<div class="col-6"><a href="/contact" class="btn btn-block btn-primary">Contact</a></div>
<div class="col-6"><a href="tel:123-456-7890" class="btn btn-block btn-primary">Call</a></div>
</div>
</div>
Contact, Directions & Call button
<div id="footer-contact" class="container">
<div class="row">
<div class="col-4"><a href="/contact" class="btn btn-block btn-primary">Contact</a></div>
<div class="col-4"><a href="tel:123-456-7890" class="btn btn-block btn-primary">Call</a></div>
<div class="col-4"><a href="https://www.google.com/maps" class="btn btn-block btn-primary">Directions</a></div>
</div>
</div>
