start_flash.sh fails with "ImportError: No module named 'Cryptodome'

Here's the output - any ideas?

```
Starting smart config pairing procedure
Waiting for the device to install the intermediate firmware
Traceback (most recent call last):
File "./smartconfig/main.py", line 15, in
from smartconfig import smartconfig
File "/home/openhabian/tuya-convert/scripts/smartconfig/smartconfig.py", line 43, in
from multicast import multicast_head, encode_multicast_body
File "/home/openhabian/tuya-convert/scripts/smartconfig/multicast.py", line 12, in
from Cryptodome.Cipher import AES
ImportError: No module named 'Cryptodome'
........................................................................................................................
Timed out while waiting for the device to (re)connect
```

I've tried "pip install pycryptodome" but that didn't resolve it. Also tried "pip install pycryptodomex" also with no success.