Junnam,
One more thing (in addition to Mike’s pointer to the Download and Embedding notebook) is that you will notice that all the files will be downloaded and locally referenced (scrubber, solar-path, etc.) except for the code that is required from external repositories, in this case:
require("d3@5")
require("solar-calculator@0.2")
The easiest way around that is probably to redefine these as described in this thread: Understanding Observable - Downloading HTML & JS
Good luck and let us know how it goes.