I tried copying my design into Site. It looks good in this editor view with Gobold from Google Fonts:

But there are still Missing Fonts notices:

I replaced so many times but it could not show up in preview:

Sorry that this is my private work so I cannot share the file, but I hope somebody could guide me to the solution, or explain what happens to the fonts in editor and in preview. I can describe the situation as detailed as you need.
Do I need to do any extra steps to get these fonts showed up in my site?