MySensors Configuration Error

Hello,

I’m new to the community. Been using Hass.io (0.68.0) for a while with 3rd party sensors but would like to start making my own.
I’ve made a MySensors Serial Gateway but am struggling to get the configuration to work in HA.

Here is what I have in my config

mysensors:
  gateways:
    - device: '/dev/ttyUSB0'
      baud_rate: 38400
  optimistic: false
  persistence: true
  version: '2.0'

and this is the error I get when I check my config:

Invalid config for [mysensors]: not a valid value for dictionary value @ data['mysensors']['gateways'][0]['device']. Got '/dev/ttyUSB0'. (See /config/configuration.yaml, line 211). Please check the docs at https://home-assistant.io/components/mysensors/

Didn’t know if it was due to the device path being wrong so tried to check on the terminal using:
hassio host hardware
but get the following error:
Error decoding json invalid character ':' after top-level value: 404: Not Found

Any help would be greatly appreciated!

Thanks, Andy

This one is working:
mysensors:
gateways:
- device: ‘/dev/ttyUSB0’
persistence_file: ‘/config/mysensors.json’
baud_rate: 115200
optimistic: false
persistence: true
retain: true
version: ‘2.0’