Hi Mabel
Thank you very much for the fast reply. I knew the function you sent me with addDays. For testing purposes I wanted to use addMinutes. I got this figured out now:
@less(formatDateTime(addMinutes(item()?['Created'], 1),'yyyyMMddHHmmssffff'),utcNow('yyyyMMddHHmmssffff'))
Here for the community my flow to delete old files. Special in this flow is that I don't want to delete folders, otherwise younger files may be deleted along with an old folder.
To do this I added the following filter query to the "Get Files (properties only)" action:
ContentType eq 'Document'
Here the screenshot of my small flow

Best Regards
Diego