How do I know that the project has been rendered on the server side?

the original react single-page application of SPA has been changed to server rendering page according to the demo, on the Internet. However, opening the corresponding route through node and checking the source code with ctrl+u is still the most original index.html code. Is this server rendering? I understand that the server should be able to see the complete html code after rendering?
ctrl+u View Source Code:


<!doctype html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1,shrink-to-fit=no"><meta name="theme-color" content="-sharp000000"><link rel="manifest" href="/manifest.json"><link rel="shortcut icon" href="/favicon.ico"><title></title><link href="/main.css" rel="stylesheet"><link href="/static/css/main.css" rel="stylesheet"></head><body><noscript>You need to enable JavaScript to run this app.</noscript><div id="root"></div><script type="text/javascript" src="/static/js/main.js"></script></body></html>

your rendering is not successful. Server rendering refers to, for example, react, renders the react component on the server, and then the server renders it as a html string and returns it to the browser to display it directly.

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1beb446-31a67.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1beb446-31a67.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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