When I try to update or install one of your components (modals for example) here's the error message we get:

0: RegularLabsInstallerScriptHelper::preflight(): Argument #2 ($adapter) must be of type JAdapterInstance, Joomla\CMS\Installer\Adapter\LibraryAdapter given

0: PlgSystemModalsInstallerScriptHelper::preflight(): Argument #2 ($adapter) must be of type JAdapterInstance, Joomla\CMS\Installer\Adapter\PluginAdapter given

We already had the extensions installed in Joomla 3 but we can't manage to update or install the Joomla 4 versions.

Could you help me?

Yes, I've downloaded the latest version.
The currently installed version of Joomla! is "4.3.4"