// check if receiver is the same as the sender of the tx
ensure!(
    receiver == info.sender.to_string(),
    ContractError::Unauthorized
);
ensure!(
    receiver == info.sender.to_string() || info.sender == env.contract.address,
    ContractError::Unauthorized
);
ensure!(
    receiver == info.sender.to_string(),
    ContractError::Unauthorized
);
