I want to talk apple customer care
I have received message over calendar application and says threats on your I phone
Question marked as
Are you seeing something as shown in pic below?
Then probably you have accepted an offer or subscribed for a spam Calendar accidentally. Watch the GIF below to know how to unsubscribe from these alerts. Look for an unknown Calendar on the device under subscribed calendars.
iOS / iPadOS devices cannot be hacked or infected with Virus / Malware / Spyware, unless you have intentionally downloaded spurious softwares or unauthorised apps directly from internet and installed on your device or/and have Jail Broken.