Problem of slug /en/ not being displayed

Hello,

I installed polylang and set my default language to English and then added the French language.

My problem is that on my main language in English the url don’t appear with the slug /en/ :
Example :
https://monurl.com/
https://monurl.com/our-360-plateforme/

Then when French the slug /fr/ appears :
Example :
https://monurl.com/fr/accueil
https://monurl.com/fr/notre-plateforme-360/

Can you tell me where to modify this ? Or can it be a bug ?
Thanks for your feedback,

Aymeric