
Hi @Andy ,
As SharePoint workflow is retired on SharePoint online, you could use Power Automate flow to send notification.
1.Create a scheduled cloud flow(repeat every 1 day).
2.New step "Get files(properties only)"
Select you site and library > add "Filter Query" > Expired Date eq Expression"addDays(utcNow(),2,'yyyy-MM-dd')"
3.New step "Apply to each" > Add an action > Send an email(V2) > select "Created By Email"
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.