Custom invitation messages


I wanted to know if it is possible to use a custom invitation message when inviting people to a calendar event. For example, in outlook it is possible to attach formatted text (like in an E-Mail) to a calendar invitation. In this text one can explain the reasoning for the event and invitation. Currently, I am writing the E-Mail separately and then referring to the calendar invitation in it, which I then send a couple seconds later. I would like to be able to send this both in one mail/calendar invite. Is there any way to do this?

I do not need to send custom messages to each participant, I just want to send a general inivitational mail.

Kind regards