I'm not sure what you mean exactly.

If you refer to have JSItemap generating the AMP sitemap, it's because it must be enabled. It's written at this FAQ: https://storejextensions.org/faq/why-the-amp-sitemap-is-empty.html

By the way this is optional. JAmp generates meta tags to instruct Google about AMP links, in the source code of AMP enabled pages, you see the AMP link meta tag.

There are no Google tests saying that a website is 'amp compatible'. There are AMP urls used by Google to retrieve the AMP version of pages.