Error in py_module_import(module, convert = convert): ModuleNotFoundError: No module named 's2a'

Hi!
I just installed the package and am trying to run `PAGA()` on a Seurat object. However, I am encountering the error:

```
> a = PAGA(sobj)

Error in py_module_import(module, convert = convert): 
ModuleNotFoundError: No module named 's2a'
```

Any idea what the issue may be?

Thanks in advance!

Cheers,
Marta 
