'numpy.ndarray' object has no attribute 'ratio_clip'

When I train AgentDDPG, this error happen.
In elegant_finrl/agent.py line 278 function select_action:
```
def select_action(self, state) -> np.ndarray:
states = torch.as_tensor((state,), dtype=torch.float32, device=self.device).detach_()
action = self.act(states)[0].cpu().numpy()
return (action + self.ou_noise()).ratio_clip(-1, 1)
```

`action + self.ou_noise()` is a np.ndarray, it has no attribute named "ratio_clip".