Could not find any [key] keyword in the A column of the CSV file

I have this error but all is well configured.
Why?
**_Service: csv
Invalid format: Could not find any [key] keyword in the A column of the CSV file_**

```
[key];en;it
hi;Hi;Ciao
```

```
platform :swift
formatting :none
output_path '../Resources/Translations'
source :csv,
       :path => 'pippo.csv',
       :column_separator => ';'
```