You can now withdrawal OBT from the Oobit platform to your external wallet. Due to the OBT token being an ERC-20 token standard, this means that the Ethereum blockchain facilitates all OBT transactions. And in order to execute a transaction on the Ethereum blockchain, one needs to pay gas fees.
Gas fees are small denominations of ETH (known as gwei) that are paid to the miners executing the transaction for their time and effort. Without paying the fee, transactions are not processed.
Therefore, in order to send OBT, one will need to have ETH in their Oobit wallet. Please note that ETH is not required when buying, storing, converting or receiving OBT tokens.