Accessibility: blind mode... where is the button?

Hi

I've been watching a lot of videos about blind mode, and there was a button to activate this mode... but, in this moment I don't find it.
Can someone help me, please?

Thank you.

https://lichess.org/account/preferences/game-display

In the above link go to ‘Blindfold Chess(invisible pieces)’ and then click on ‘Yes’.