Fitvids library is not detected

I've fixed the video width issue by adding this to my theme css, so I don't need fitvids anymore. This doesn't mean the open issue is fixed, but I have lowered the priority.

.field--name-field-media-oembed-video {
  position: relative;
  overflow: hidden;
  width: 100%;
  padding-top: 56.25%; /* 16:9 Aspect Ratio (divide 9 by 16 = 0.5625) */
}

/* Then style the iframe to fit in the container div with full height and width */
.media-oembed-content {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 100%;
}

Please see this issue for how to get the library to install without downloading manually: 📌 Add composer.json file Needs work