BTB-manager-telegram: i18n translation other than en break bot commands

Traceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/home/ubuntu/titus/BTB-manager-telegram/btb_manager_telegram/__main__.py", line 149, in <module>
    main()
  File "/home/ubuntu/titus/BTB-manager-telegram/btb_manager_telegram/__main__.py", line 97, in main
    from btb_manager_telegram import handlers
  File "/home/ubuntu/titus/BTB-manager-telegram/btb_manager_telegram/handlers.py", line 665, in <module>
    FALLBACK_HANDLER = CommandHandler(i18n.t("keyboard.fb_cancel"), cancel)
  File "/home/ubuntu/titus/BTB-manager-telegram/venv/lib/python3.8/site-packages/telegram/ext/commandhandler.py", line 163, in __init__
    raise ValueError('Command is not a valid bot command')
ValueError: Command is not a valid bot command