I'm not able to trigger e-mails from Flutterflow

[matildetrevi]

Hello everyone,
I have installed the Trigger Email extension for Firestore in my Flutterflow project.
If I access Firebase and try to create a document in the "mail" collection as explained in this tutorial everything works perfectly: the "delivery" field is automatically created and the mail arrives at the recipient.

The problem is that I am not able to generate the documents directly from the Flutterflow app.
I have created a customised data structure within Flutterflow to reproduce that of Firebase, but I would like to be able to manually set the startTime within the Info field, so that I can automatically send the mails on a certain date in the future.
However, if I create a document from FF with the startTime filled in, the mail is not sent.

This is the document made through FlutterFlow:

And this is an example of a document created through Firebase:

Thank you for the help!