bot.py fails with type error "object is not subscriptable" line 78

Python 3.8.0
Poetry (version 1.3.2)

```
Traceback (most recent call last):
  File "bot.py", line 78, in <module>
    def __is_out_all(cmd: str) -> tuple[str, bool]:
TypeError: 'type' object is not subscriptable
```