Debian package management - warning and error message

i'm trying to generate a debian file for a flutter project with flutter_to_debian lib but i meet 2 issues:

1. i have a warning. i don't understand why "The creator of a debian package has 100% access to every parts of the system it's installed"

2. i have an error exit. i don't know why

Here's my logs:

réparation du dépaquetage de aewallet_2.0.8_amd64.deb ...

⚠️  ⚠️  ⚠️  Warning!

The creator of a debian package has 100% access to every parts of the system it's installed

Maintainer: Archethic

Description: Decentralized & cryptocurrency non-custodial hot wallet on Archethic blockchain

Sure you want to proceed with the installation of this package (yes/no) ?:
y
dpkg: erreur de traitement de l'archive aewallet_2.0.8_amd64.deb (--install) :
 new aewallet package pre-installation script subprocess returned error exit status 1
Des erreurs ont été rencontrées pendant l'exécution :
 aewallet_2.0.8_amd64.deb

and my config

flutter_app: 
  command: aewallet
  arch: x64
  parent: /usr/local/lib

control:
  Package: aewallet
  Version: 2.0.8
  Architecture: amd64
  Essential: no
  Priority: optional
  Depends: libsecret-1-0,libjsoncpp1
  Maintainer: Archethic
  Description: Decentralized & cryptocurrency non-custodial hot wallet on Archethic blockchain

Any idea ?

Thank you

This warning is issued by postinstall script generated by flutter_to_debian.

To disable it, use nonInteractive flag:

flutter_app:
  nonInteractive: true

Current latest release (1.0.4) does not include this flag, as mentioned in this issue, so you can use the command suggested in that issue:

dart pub global activate https://github.com/jeffrey0606/flutter_to_debian.git --source git