Are you talking about c4g.io’ plugin ? GitHub - code4game/glTFForUE4: Import glTF 2.0 in Unreal Engine
Is this related to the original poster experimentation ? I don’t see him talking about installing any plugin when importing a gltf file.
It seems to be supported natively from 4.19 according to its post.
Anyway the c4g plugin isn’t available for 4.20 and it’s not on the marketplace, I’m not sure if this is just a POC or actively maintained.