Hello
If you are using personal Microsoft account, this is not possible with Outlook Classic, it is for business tier licensed users only.
If it is New Outlook, it can be done when you create a new item from calendar, the Teams toggle is there for you to turn on/off. HOwever, this is only working if your microsoft account is using native outlook.com/hotmail.com address, if you are using non Microsoft native domain, such as gmail, yahoo, etc, it will not work.