There's no way of knowing for sure without the documentation (or whatever substitutes for it) for that PCB. Keep in mind that you are asking strangers on an internet forum that know nothing about that board -- we have to take your word for it that it even has anything to do with speakers and not tire pressure sensors -- so we are a pretty poor resource for reliable information about what you can and can't do unless you give us a lot more to go on.

Having said that, and making some assumptions, it is most likely that the idea is for you to take the R+ and R- wires to drive the right speaker and similar for the left.

 

If the monitor doesn't already have speakers inside, the board isn't likely to have the amp chip and related components installed either.