Generate calendar phone entry

Hello,

Do you know if there is a way to generate a new calendar event for both iOS and Android ?

My need is to allow my users to add meeting note for future events, and I want them to tick a box to create an event in the phone calendar thanks to ICS or something like that.
I create an event > I tick "Add this in my calendar" > OS Popup to add it to calendar.

I Found this but before moving forward, I wanted to ensure that you already needed something like this.

Thanks for your help.