Usually the iOS standard way works fine with Zendesk WeekCal as well. Please try that first. If you have problems, try the following method instead.
On the 달력 page, select a calendar you like.
Click 선택하다.
If you are not logged in to WebCal.Guru, you will not be able to modify subscription settings and you will have significantly smaller selection of calendars. In this case, jump directly to Step 4.
Adjust the subscription settings if needed and click 내 캘린더에 추가.
You will be taken to 내 캘린더 page. On the calendar you just added, click next to 다운로드 and select 클립 보드에 주소 복사.
On the home screen of the device, tap Settings.
Turn the device to portrait orientation, scroll down to Calendar and tap it.
Tap Accounts.
Tap Add Account.
Tap Other.
Tap Add Subscribed Calendar.
Tap the empty input field.
Tap Paste.
Tap Next.
Tap Save.
Updated 8 Feb 2023