How to use the fastecdsa.ecdsa function in fastecdsa

def sign_raw_data(raw_data, privatekey_hex):
    """
    Sign a string of data.
    Returns signature as a base64 string
    """

    # force uncompressed
    priv = str(privatekey_hex)
    if len(priv) > 64:
        assert priv[-2:] == '01'
        priv = priv[:64]

    pk_i = int(priv, 16)
    sig_r, sig_s = fastecdsa.ecdsa.sign(raw_data, pk_i, curve=fastecdsa.curve.secp256k1)

    # enforce low-s 
    if sig_s * 2 >= fastecdsa.curve.secp256k1.q:
        log.debug("High-S to low-S")
        sig_s = fastecdsa.curve.secp256k1.q - sig_s

    sig_bin = '{:064x}{:064x}'.format(sig_r, sig_s).decode('hex')
    assert len(sig_bin) == 64

    sig_b64 = base64.b64encode(sig_bin)
    return sig_b64

"""
        if self.is_coinbase():
            return
        for vin in self.Vin:
            if not prev_txs[vin.txid].ID:
                raise ValueError(
                    "Error: previous transaction is not correct."
                )

        tx_copy = self.trimmed_copy()
        for inId, vin in enumerate(tx_copy.Vin):
            prev_tx = prev_txs[vin.txid]
            tx_copy.Vin[inId].signature = ""
            tx_copy.Vin[inId].pubkey = prev_tx.Vout[vin.vout].pub_key_hash

            r, s = ecdsa.sign(tx_copy, priv_key)
            signature = "".join([str(r), str(s)])
            self.Vin[inId].signature = signature
            tx_copy.Vin[inId].pubkey = ""

def sign_msg(msg: str, priv_key: str) -> str:
    '''
    Given a message, and the private key,
    return the signature (in hex). x, and y are joined
    with 'x'
    '''
    r, s = ecdsa.sign(msg, int(priv_key, 16))
    return '{:x}x{:x}'.format(r, s)