By default, when users click sharing link in the notification email, the file will open in the browser.
You will have to manually create a sharing link in below format.
The link will open in the browser directly:
https://tenant.sharepoint.com/sites/site1/Shared%20Documents/excel1.xlsx
This link will prompt user to open in the client application:
ms-excel:ofe|u|https://tenant.sharepoint.com/sites/site1/Shared%20Documents/excel1.xlsx
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