In OBS:
+ → Browser → paste the link into the
URL box (
do not tick "Local file") → about
700 × 440 when it is always open, or
1920 × 1080 when it flies in.
Turn off "Refresh browser when scene becomes active" — that would wipe the book.
Chat commands
viewers — !sign your message · !guestbook shows the latest page
you & mods — !page 3 · !turn / !prev · !erase name (their latest line) · !pin text (sign as you, no cooldown) · !clearbook
Backups: ⚙ on the widget (OBS → Interact).