so the deposit shows up on house detail section such as cost per night, cleaning fee, deposit...however when someone books it does not charge them that I can see the security deposit
If you read through information for hosts on the BnB site you will see the deposit isn't physically taken - but this amount is held against a card and can be used in the event of damage to property etc.
Read up on how the security deposit works and what it is for. Make sure you also know the other basics like what to do/not to do for cancellations - otherwise you will find yourself in a bit of a mess!