Lottie-player.js:12 Uncaught (in promise) TypeError: customElements.upgrade is not a function

Anyone seen this error before?

I’m using Onsen UI

<script src="https://unpkg.com/@lottiefiles/lottie-player@latest/dist/lottie-player.js"></script>
<lottie-player src="https://assets5.lottiefiles.com/packages/lf20_ttz7k6cj.json"  background="transparent"  speed="1"  style="width: 300px; height: 300px;"  loop controls autoplay></lottie-player>