Some apps might require extra packages.
You can easily add additional python packages in AppDaemon (HomeAssistant).
Go to your HomeAssistant Settings -> Add-ons -> AppDaemon -> Configuration -> 3 dots -> Edit as YAML
By default your config should look like this:
init_commands: []
python_packages: []
system_packages: []
Just add all the needed packages as a list to "python_packages":
init_commands: []
python_packages:
- pillow
system_packages: []