How to remove a virus from my Calendar on iPhone?

You got tricked into installing a rogue calendar; your phone does not have a virus.

If your phone has iOS 13 or earlier: Go to Settings/Passwords & Accounts, look under Subscribed Calendars, tap on the offending calendar and delete it.

If your phone has iOS 14: Go to Settings/Calendar/Accounts, Tap Subscribed Calendars, tap on the offending calendar and delete it.

And in the future beware of "free" offers

Follow the steps here -> If you see 'apple.com/bill' on your billing statement - Apple Support

It isn't a virus, it is a subscription calendar you agreed to take.

Wrong link 😏

Yep, I don't multitask as well as I used to and I've been filling in government forms all day.

You have my sympathy.

How I can remove viruses from my phone

How can I remove viruses from my calendar

Read the Apple Recommended post at the top of the page that both of your posts appear on.