Public Shared Link Not Working

Public Shared Link Not Working

I want to share my notes to my colleagues. 

So, I clicked the Shared link or Get public link button.

And then, I gave the link to colleagues.

The problem is my colleagues, cannot open the link.

I tried by myself also by pasting the link to my browser, and the error message  "This site cannot be reached."

Please help me to fix this.

Thanks.