Microsoft Teams Integration
Starting in Fantastical version 4.1.9, if you have a professional or school Microsoft 365 account, you can choose to add a Teams meeting to events on calendar accounts other than Microsoft.
Adding your Microsoft account
Add your Microsoft account by opening Fantastical's Settings, tapping Accounts, tapping Add Account, then selecting Microsoft 365. Sign in to your Microsoft account and it will appear in Fantastical's list of accounts.
Enable the Teams option
After your Microsoft 365 account has been added, tap it to view the details, and enable the option to Allow creating Microsoft Teams meetings on other accounts

Once enabled, you can add a Team meeting to events created on non-Microsoft accounts. Tap on the Show More button when creating an event, or tap an event on your calendar to view the details, then select Edit in the top right corner. In the event details, toggle on the option for Microsoft Teams Meeting, and save the event. The Teams meeting info will automatically be added to the event's notes.
Need to remove a Teams meeting that you already created? Toggle off the option for Microsoft Teams Meeting, then save the event.