Trigger email automation after 90 days of no bookings

Question:
How do I trigger an automated email after a contact hasn’t booked a session in the last 90 days

Product:
Wix Studio / Wix Booking

What are you trying to achieve:
I am trying to get an automated email to send to contacts that haven’t booked a session in the last 90 days.

What have you already tried:
I have set up a segment with the following conditions:
If / Last booked session / in the last 90 days

Fairly new site, which was launched in Jan 2024, but this seems to populate with all the contacts that have booked a session in the last 90 days

I have an automated email set up, to send based on the specific segment and is triggered when people leave the segment

Is this correct? or have I totally got this wrong. Thanks, Marc