If you need to make sure your comouter doesn’t go to sleep, with the recent addition of wakelock to Chrome this is extremely easy to do.
Open Chrome on any page
Open the developer tools:
Ctrl+Shift+C on Windows/Linux
or
⌘ +⇧+C on Mac (Cmd+Shift+C)
will open the dev tools - then go to the “Console” tab and paste/type this into the console
let screenLock = await navigator.wakeLock.request('screen');
That’s it. Your computer won’t sleep.
Note that you will lose the lock if you clos or change the tab.