i didn’t use this plugin but if i were you i use .htacces to redirect mobiles users to amp url
Assuming your amp version is under /amp (http://example.com/amp), you can try redirecting your visitors in your .htaccess file like this:
RewriteEngine On
RewriteCond %{REQUEST_URI} !/amp$ [NC]
RewriteCond %{HTTP_USER_AGENT} (android|blackberry|googlebot\-mobile|iemobile|iphone|ipod|\#opera\ mobile|palmos|webos) [NC]
RewriteRule ^([a-zA-Z0-9-]+)([\/]*)$ https://example.com/$1/amp [L,R=302]
source: https://stackoverflow.com/questions/36171028/how-can-i-redirect-to-amp-version-of-website-on-mobile
BTW google automatic use amp url if its detect AMP version on your website
for testing purpose open new tab and press F+12 and the upper left corner click mobile button and select any device and refresh and search your website whole URL in same tab so you can see how your website looks in google search.
you should wait at-least 7 days after updating your website structure