what are the Off-chain transactions ?
Off-chain transactions refer to those transactions occurring on a cryptocurrency network which move the value outside of the blockchain.
https://www.investopedia.com/terms/o/offchain-transactions-cryptocurrency.aspYou can at least try to use your browser to get at least a small information about what off-chain transaction is. I think that you can imagine what the off-chain transaction looks like by opening or read the definition of it.