def METHOD_NAME(hex_packet: str) -> str:
    """Sign the packets with the designated crc key.
    Args:
        hex_packet: packet to sign.
    Return:
        The calculated and signed packet.
    """
    binary_packet = unhexlify(hex_packet)
    binary_packet_crc = pack(">I", crc_hqx(binary_packet, 0x1021))
    hex_packet_crc = hexlify(binary_packet_crc).decode()
    hex_packet_crc_sliced = hex_packet_crc[6:8] + hex_packet_crc[4:6]
    binary_key = unhexlify(hex_packet_crc_sliced + "30" * 32)
    binary_key_crc = pack(">I", crc_hqx(binary_key, 0x1021))
    hex_key_crc = hexlify(binary_key_crc).decode()
    hex_key_crc_sliced = hex_key_crc[6:8] + hex_key_crc[4:6]
    return hex_packet + hex_packet_crc_sliced + hex_key_crc_sliced