I wonder if it is possible to get a notification from SharePoint Online if a file from my document library is NOT modified/updated at a specific date/time using Power Automate.
Can anyone advise please.
Just like Ganesh said, a daily recurrence flow with a condition check on the modified date seems to be a good option for you. You can set the modified date to compare with the created date or a specified date set by you. Here are examples for your reference: