Missing language code in permalinks

Dear all,

I successfully migrated all contents from WPML to Polylang with this plugin. The only problem is that the language code in permalinks is missing. As a consequence, pages with the same title have the same permalinks and I cannot switch language between these pages.
Example:
– Page title “Test”
– permalink in the default language: https://example.org/test

If I create a translation in English for this page using the same title “Test” the permalink is https://example.org/test while it has to be https://example.org/en/test

Any suggestions?

Thanks

Maurizio