How to use the bitbox02.bitbox02.btc.TBTC function in bitbox02

def coin_network_from_electrum_network(self) -> int:
        if constants.net.TESTNET:
            return bitbox02.btc.TBTC
        return bitbox02.btc.BTC

self,
        keystore: Hardware_KeyStore,
        tx: PartialTransaction,
        wallet: Deterministic_Wallet,
    ):
        if tx.is_complete():
            return

        if self.bitbox02_device is None:
            raise Exception(
                "Need to setup communication first before attempting any BitBox02 calls"
            )

        coin = bitbox02.btc.BTC
        if constants.net.TESTNET:
            coin = bitbox02.btc.TBTC

        tx_script_type = None

        # Build BTCInputType list
        inputs = []
        for txin in tx.inputs():
            my_pubkey, full_path = keystore.find_my_pubkey_in_txinout(txin)

            if full_path is None:
                raise Exception(
                    "A wallet owned pubkey was not found in the transaction input to be signed"
                )

            prev_tx = txin.utxo
            if prev_tx is None:
                raise UserFacingException(_('Missing previous tx.'))