@Elyas4 the best way to collect a real security deposit is to list on platforms other than Airbnb.
However, if you want to try it on Airbnb, you must (a) disclose on your listing that you will charge this deposit separately and in addition to the guest's regular payment, (b) collect it by requesting money in the resolution center, which you can only do after their regular payments are completed (and you don't get any notice about when this is), and (c) be prepared that Airbnb customer service will not back you up if you attempt to withhold reimbursement after the stay.