Go to the page ContextMenu and with Ctrl and u the source code is displayed. With Ctrl and a you mark the whole code. Then Ctrl and c to copy and with Ctrl and v you paste it into your code editor. Now you can save the code.
If you also want to have the correct version of the scripts, click in the code on
…/js/three.min.112.js
or
…/js/OrbitControls.js
Then you can copy them just as well.