So to make this possible, I should activate beta feature in addition to discussion tools? Understood! But it should have been written in Tech News or somewhere, Tech News just said what you said here:
It’s already live, see Speciální:Nastavení#mw-prefsection-editing-discussion (setting Aktivovat experimentální nástroje v editoru zdrojového kódu…).
Regarding making sure people are/were aware of this new functionality, there was an announcement in Monday 17 May 2021's installment of Tech News [i]. If you think that message could've been more effective had it been communicated in a different way, please let us know.