Here's an example bash script that should accomplish what you're looking for:

```
#!/bin/bash

# enter the directory you want to search for json files
cd /path/to/directory

# recursively search for all json files and output their names and sizes
find . -type f -name "*.json" -exec du -h {} \;

exit 0
```

Save this as a file with a `.sh` extension, then make the file executable with the command `chmod +x filename.sh`. When you run the script, it will change into the directory you specify and use the `find` command to locate all files with a `.json` extension. The `du` command then outputs the file size along with the filename.
Scrivi uno script bash per trovare tutti i file json in modo ricorsivo all'interno di una directory e generarne i nomi e le dimensioni.