Problem with the app CALENDAR

Hello,

There is a new subscription on the app CALENDAR in my iPhone. The problem is that the subscription came up from nowhere because I did not subscribed to it.

It is called “Click Ok to continue” and it set the calendar to remind me to click on a specific link every hour.

I have been trying to delete this subscription but there is not the option to delete it as in the other subscriptions.

I would like to know how I can delete this subscription from my calendar.

Also, is it a type of some virus? Will I have problem with my IPhone? Will there be any charges?