Not exactly. You can link to a specific page by using the page’s path, but it will start a new session, meaning you will reset Session State. You’d need to build a custom component that if you want to display custom HTML that communicates with the Python server to perform an action within a session.
And you have some <ip:port> to access your app, then the address of the a_page.py file is: <ip:port>/a_page
Therefore, you can add a link to that page in Markdown, like this:
import streamlit as st
st.markdown("Go to [Page A](/a_page)."
However, this type of link will not preserve Session State so it may not be an adequate solution. I don’t have an example using a custom component, which is necessary if you want to preserve the session.