Can you HELP! How to trigger an action on change of cell?

Hi all
I am looking at how to trigger an action from a change of cell within a glide table - no the clicking of a button. The example would be to send an email when a date is upcoming i.e. when a date occurs in 30 days, send the user an email based on cell in that row?
A lot of the action tutorials are based on the user being active within the system, however this would be trigger when a user is not logged in and requires a reminder/prompt to go into the app.
I can see how this is done, however cannot seem to make it work within my app.
Thanks in advance

This is why it is always best to have Google Sheets as your database… and let Google Scripts do all triggers and integrations.

At the moment, time-based triggers are not supported within Glide Tables, but we expect it to be there before the end of the year.