remove calendar spam from iphone 17.2 if unsubscribe isn't available
I have phishing/Spam appointments scheduled to my iphone calendar, version 17.2. I read some previous instructions stating that I need to click on "unsubscribe." Unsubscribe isn't available on this appointment. I've clicked on Delete. It deletes and then re-adds the appointment. Please advise on how to remove these spam appointments.
iPhone 13, iOS 17