[Polylang] Language section is not visible in Edit

Hello,

I’am using polylang and I am trying to make a nexMove page in EN/FR.
it seems the language block in the edit function is not displayed (at all) like in the doc:
https://xlplugins.com/docs/nextmove-woocommerce-thank-you-page/how-to/how-to-make-nextmove-polylang-compatible/
Any idea to what i must do ?

Polylang is working fine and NextMove also.

Best regards,