The new feature hasn't been released to Google Play Store yet, but you can exercise it in Android Studio at the moment.
Start here with the Custom Sharing feature documentation in the Fedilab app at:
which shows you how to test against a sample site, e.g. teci.world
Then, you can look at the content creation management system that Tom created today, that uses the Custom Sharing feature, with more features and security, at:
Those who label words as violence do so with the sole purpose of justifying violence against words.