how do i update Google AMP cache

I’m using amp as a subdomain. The amp pages are refreshing when I add a new post. However, google amp cache is not being refreshed. Is there a reason? I read the google document to update, but I haven’t found a way to run the sample code. Is there anyone here who has experience with this?

I am using ampforwp plugin but ı am not using AMP Cache extention. I generate and direct the URLs myself. I’ve entered new content, but google hasn’t received a cache for more than 1 day.

How can ı clear my google amp cache.