Unsubscribe from calendar in iOS calendar app

I accidentally subscribed to a calendar I don't want on my iPhone and I can't figure out how to get rid of it. I can easily hide it in the Calendar app, but I can't find how to unsubscribe from it.

I searched online for how to unsubscribe, and it said that if I click on the "i" button on the right of the calendar, there would be a "delete calendar" button, but there isn't. I can find the "delete calendar" button for the "personal" and "work" calendars that are there by default, but not on the calendar I want to delete. All I can do when I click on the "i" button is rename the calendar, change its color and choose if I want to get notifications from it.

("Prenumererad" means "subscribed")

I also tried to delete the calendar online from http://icloud.com, but it didn't show up on iCloud. Since I use a Google account, I also tried to delete it online from Google calendar, but it wasn't there either.

I also tried deleting and reinstalling both the Calendar app and the app that installed the unwanted calendar, but it was still there after I reinstalled the app. The app which installed the calendar only has a "subscribe to calendar feed" button (which was the one I accidentally clicked on) and no "unsubscribe from calendar feed" button.

How do I unsubscribe from this calendar?

Local Subscriptions

Calendars you subscribe to locally can be removed under Settings > Passwords & Accounts > Subscribed Calendars > [the calendar in question] > Delete Account. Sourced from MacRumors.

Cloud Accounts

Calendars you subscribe to via Google Calendar can be removed from the website.

Calendars you subscribe to through iCloud can be deleted from the info view.