how to update signature

hey, i call my wallet to sign the transation, and then i need to set the signature to the transation, but i got this error: 

```
Cannot assign to 'script' because it is a read-only property.
```

<img width="1793" alt="image" src="https://user-images.githubusercontent.com/995909/190936556-59ccd697-bb02-44d0-80b5-72215239a65e.png">
