Is there a way to show pdf file name while it is displaying?

[ariehen]

You may have gotten this already, I just noticed the topic, but you could try this CSS snippet. Adjust the font-size, etc., as desired.

.internal-embed.pdf-embed:not(.media-embed)::before {
    content: attr(alt);
    font-size: 0.9em;
    font-weight: 600;
    color: grey;
    padding-bottom: 2px;
}