If you you DOM to show your RSS in your HTML you will find the in the end of the content "Continue reading" and with the permalink(). You can check my feed here
This is the script before end of tag
<p class="link-more"><a href="https://www.eitren.com/blog/products/bagaimana-cara-page-halaman-link-website-di-halaman-pertama-google-search-engine/" class="more-link">Continue reading<span class="screen-reader-text"> "Bagaimana cara page/halaman/link website di halaman pertama Google Search Engine?"</span></a></p>]]></description>
I would like to modify the link add /AMP/ at the end of link. So it would become "...google-search-engine/amp/" class...
It depends on what specifically your RSS feeds are set to display. Some show full posts, others excerpts. It looks like in your case you can filter this text with the
the_content_more_linkhook.function wpse_send_to_amp() { return 'Continue reading'; } add_filter( 'the_content_more_link', 'wpse_send_to_amp' );