Enable APO - setup

I’ve setup the first Wordpress website with APO function.
In the plugin I’ve enabled the setting and I also activated it in the Cloudflare setting.

However, when I check the ‘speed’ section, by ‘Recommended Optimizations’ there is the button to enable it. So I was surprised and tried it again. But this button is not changing after updating the page.

To be honest, I don’t understand the way to check if APO is activated or not. I’m not familiar with Curl using.
Is there another way to check this, or is it okay?