Can the front-end project based on cesiumJS be fully localized?

I want to develop a 3-D earth satellite project through cesiumJS. I know that token is necessary to display a 3-D earth, but can I display a earth locally? Moreover, whether the follow-up development can be fully localized, such as simulating the movement of satellites?

As long as the data you’re loading is from local sources, then CesiumJS can run without an internet connection. Here is a code example showing how to turn off all online resources that will run completely offline:

Cesium ion’s global imagery and 3D terrain can be used locally with an on-premise license, see: