Eyes,
then ink.
Sit in the call. Look at each other, not at the screen. Write whatever comes, without reading it back. When the time is up, you both turn the page.
Your words stay invisible while you write, are sent only when the round ends, and are scrambled with the room code so only the two of you can read them. Nothing is stored anywhere.
Read this aloud.
…
The other person opens this same page, chooses I have a code, and types it in.
min
Waiting for them to arrive
What's the code?
You're in.
Waiting for them to begin
5:00
Set your pen down.
Waiting for them to finish.