Import event from ics into Outlook

I use Outlook web client, https://outlook.office.com/calendar, opened in a web browser (Chrome on Linux).

I have a .ics file containing details of an event. The ics file was attached to a received email and I downloaded it to my local machine.

I want to add this event to my Outlook calendar. I don't see any "import" or similar options in the Outlook Calendar web client. How can I import it?

What I've tried:

The "Help" feature in the web client brings no results when searching "ics". When searching "import", it tells you how to manually create an event in your calendar, or how to import a whole calendar (not an event into an existing calendar).

Searching on Google also gives results about importing whole calendars instead of events, and also says irrelevant things like "clicking on the .ics file will import it into your calendar" - this only works with the Windows Outlook executable application, not the web client on Linux.

Solution 1:

Outlook web client? Did you mean the Outlook on the web(OWA)?

What's the account type of your mailbox? For an office 365 mailbox, there is a button which is used to add the events in a .ics file to the primary calendar in OWA:

Edit: