How to center elements in bootstrap?

Question

<div class="container-fluid">
<div class="col-md-4">
  <div class="container">
  <img src="System admin.png" alt="Avatar" class="image">
  <div class="overlay">
    <div class="text">System Adminstrator</div>
  </div>
 </div>
</div>

<div class="col-md-4">
  <div class="container">
    <img src="Project manager.png" alt="Avatar" class="image">
    <div class="overlay">
      <div class="text">Project Manager</div>
    </div>
    </div>
</div>

Output:

I have been trying to center these two pictures over and over but can't seem to find a way to. I tried searching about grid and tried using rows and still same result.