Hi there,
There are references in the documentation to services hosted on scenesampleserverdev.arcgis.com however this deployment is old - 10.3.1 and the portal doesn't appear to be licensed. For example in here: https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-IntegratedMeshLayer.html
Either the documentation should be updated or the Portal should be upgraded and licensed.
Cheers,
Marc
Thanks. I've sent this feedback to the documentation team. As an FYI if you submit feedback directly on the help topic it will create an issue directly with the documentation team for someone to investigate.
regards,
Andrew