To withdraw from zkSync to L1 you need to pay fee. It can be paid in STORJ tokens or any other tokens which you also have on that address in zkSync, include ETH. These tokens should be on zkSync. For the storage node operator the easiest way is to choose STORJ tokens to pay fee.
If the destination L1 address (it could be any) is a deposit address of the exchange, you will get STORJ tokens there. Make sure that this deposit address is suitable for STORJ tokens (the centralized exchanges have a separate deposit address for each token/coin).
Then you can exchange STORJ tokens to what is you like - to ETH, BTC, USDT, or maybe even fiat (it’s possible for a few currencies on some exchanges).
We also expect to have exchanges on zkSync or using the zkSync to accept deposits.
See