If you have 2 Lounge passes, your lounge points will be transferred to coins every day after the game update, you can find the coins in your inbox.
If you have 2 Lounge passes and when the first pass expires, all your points will automatically convert to coins at the same time, there will a pop-up window for notification. You can also collect coins there. If you are offline when your pass expires, you will still get the notification when you log in to the game. This rule also applies when both of your passes expire.
If you have 1 Lounge pass and when it expires, you will also receive a pop-up window notification but your lounge points will remain.
*Please note that once the Lounge points convert to coins, they will be cleared.