You can disable the translate of your cpt in polylang and use translated pages to display your cpt posts. In your page template, detect if the current language is english and use your custom translation code to display those translated fields.
I want an URL like : www.domainame.com/en/
You can set it up in the Polylang url settings and hide the default /fr/
[EDIT]
To display your cpt in a page template, see this answer. Read the documentation on how to build a custom query.