Change or set passphrase
Do not use a private key as a passphrase. It is unsafe and not recommended.
The service keeps your funds on the balance of the smart contract and provides an additional level of protection of your tokens with a passphrase. Therefore, to make a transaction, you need to have access to your wallet and know the passphrase. This means that if your private key has been compromised, the attacker will not be able to use your funds if he does not know the passphrase.
Set a passphrase on the "profile" tab and top up your balance. After that, you can make transactions using the service.
No, nobody can know your passphrase via Nebulas Explorer. Only the hash of your passphrase is stored in the smart contract.
No, the passphrase cannot be recovered.
Just make a transfer to your own wallet.