It depends on the type of order you placed. In general, market orders are typically filled immediately at the current market price, while limit orders are executed when the market reaches a specific price point set by you. If your order has not been filled, it is possible that there were not enough buyers or sellers at the specific price you set.

It is difficult to give you a more specific answer without having all the deets. If you can, snap a screenshot of the order you are placing so we can break it down and explain things in more detail. (Make sure to blur or censor any private data related to your account, like your username or any other sensitive information.)