Hi @Robert5,
I am afraid that the trigger when a file is modified/updated in a SharePoint folder couldn't do that. It will be fired as soon as a file was modified.
As a workaround, how about creating a column to trigger a Flow in the SharePoint list manually?
The button as a column inserted in SharePoint list, once user finished update excel file, click the button to execute the Flow to send notification.
Here is how to use column formatting to customize SharePoint:
Use column formatting to customize SharePoint | Microsoft Docs
And this is a tutorial blog about this feature:
Button in SharePoint List to Trigger Power Automate | @WonderLaura
Best Regards,
Community Support Team _ Lin Tu
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