Google Maps has a menu to share the link of the map that already opened/customized.
The first one is copied directly to the URL address.
The second is for embedded in a blog post or website.
Especially for the second option, embedding to website, problem often occur where there is a warning: This map can not be embedded.
To solve the problem This map can not be embedded, the trick is:
Copy and paste the URL (from the first option, not from embedded option ) to a new page/tab or new window of browser.
Once the map is open on a new page, it will has the same link menu. In this menu the embedded menu is enable.