[Bug]: .env文件不知道如何修改

### Describe the bug

.env.example文件比较含糊，请问能否详细介绍一下，并加上注释，谢谢你

### Relevant log output

```shell
no
```


### Validations

- [X] Already read the README
- [X] Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.