Classic Editor
Restore the classic WordPress editor instead of the block editor.
Where to find it
SiteNivo → Settings → General → Classic Editor
How to use
1.
Enable Classic Editor.
2.
Choose mode: All Users or Per User (profile checkbox when per-user).
3.
Save Changes and open a post — Gutenberg is disabled according to the mode.
Notes
Use All Users for client sites that must stay on classic. Per User lets each author decide.