https://support.chess.com/customer/en/portal/articles/1444845-what-are-conditional-moves-
What is a "conditional move"?

they are moves you can plan out ahead.
and the computer will play them automatically when your opponent moves...
unless he does a different move then you planned. it will not move

In addition to saving time, conditional moves also serve the purpose of undermining the morale of your opponent by showing him how predictable he is and how easily he falls into your well calculated traps.
Here is a game of mine that perfectly illustrates this purpose :

How do you do them do you just pre move? That can't be the same thing as if they do something you didn't predict you could blunder?

Send a move as usual. Then find an icon under the game display with 2 bent arrows. Click it to project the opponent's move, then your reply. You can enter multiple lines. Your move registers only if the opponent makes a predicted move. This option is not available in the mobile app, just the web page.

Bump
I don't think the downvoted comments deserved to be downvoted imo
Don't bump old threads. Especially if you have nothing sensible to say.

I was saying something tho
Anyways, have a good day
If your primary reason to post is to bump, then it's better to start a new topic.
^