Adding element to youtube

I am trying to add this custom element to YouTube.

at first, I wrote in the console:

const script1 = document.createElement("script")
script1.type = "module"
script1.src = "https://unpkg.com/pose-viewer@0.0.4/dist/pose-viewer/pose-viewer.esm.js"
document.head.appendChild(script1)

and then:

document.createElement('pose-viewer')

but I got this error:

Uncaught TypeError: Class constructor a cannot be invoked without 'new' at new g (custom-elements-es5-adapter.js:11) at :1:10

so I compiled to es5:

const script1 = document.createElement("script")
script1.src = "https://unpkg.com/pose-viewer@0.1.2/dist/pose-viewer/pose-viewer.js"
document.head.appendChild(script1)

but I got this error:

Uncaught TypeError: Illegal invocation at n.f (pose-viewer.js:15) at Function.getOwnPropertyDescriptor (pose-viewer.js:15) at pose-viewer.js:44 at pose-viewer.js:58 at pose-viewer.js:130

What I am doing wrong? Why is this not working specifically on YouTube, but does work everywhere else?

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