Thank you for submitting your issue. I checked your code sample and found where is the issue. There is spacing between words “drop” and “cap” in class name in your example.
Correct class name is dropcap. Here is fixed code: <p style="text-align: center;"><span class="dropcap">W</span>e cannot walk alone. And as we walk, we must make the pledge that we shall march ahead. We cannot turn back.</p>