How used BackupManager in custom integration

I try create custom integration which use core BackupManager.

My code:
all file (if need)

from homeassistant.components.backup import BackupManager
from homeassistant.components.backup.const import DOMAIN as BACKUP_DOMAIN
from homeassistant.core import HomeAssistant


    def __init__(self, hass: HomeAssistant, config: dict, unique_id=None):
        self._hass = hass

    async def get_local_files_list(self):
        """ Get list of home assistant backups """

        manager: BackupManager =[BACKUP_DOMAIN]
        backups = await manager.get_backups()

When I run this code on development HA core all works as expected, but on real homeassistant I get Exception:

  File "/config/custom_components/yabackup/", line 202, in get_local_files_list
    manager: BackupManager =[BACKUP_DOMAIN]
KeyError: 'backup'

Where my wrong?

I will answer myself.

I try turn on backup integration directly in config and get message

The backup integration is not supported on this installation method, please remove it from your configuration

And now I have anoder question. Which right way get backup files list?