@PauloCercas
There may be another way to do it, but there is no other way to do it with that "for a selected file" way.
You can consider following alternatives:
1. Have all the files you want notifications for in a specific folder, with a Recurrence Trigger once a day, a Flow in Power Automate that iterates over all the files in that folder and sends a notification about each one.
2. Use the "for a selected file" trigger on a single text file, inside of it on each line, are the names of files that are in a specific place such as the folder mentioned above, that does similar iteration like #1 except instead of recurrence, it is by "for a selected file" trigger on a single text file - and instead of iterating every file in the folder, it might iterate only on those filenames which are matching those listed in the text file.
3. The above two are not the only ways - there are others - best one will depend on details of your scenario.
Check if above helps.
If you require that the "for a selected file" support, directly and out of the box, to select multiple files instead of one file, that will not be possible, if you really think you need this specific feature, then you can consider to submit your idea to the Power Automate Ideas Forum for further consideration.
