Probleme variable "does not exist" to back-office twig template

[Alexandre B.]

Hello, and thank you for reading.

Prestashop Version: 1.7.8.7

I'm trying to do my own meta seo preview for learning, and I could easily manage to override the emplacement of the default one. But I can't manage to get twig to recognize my variable, saying it doesn't exist. But the variable show in context:

The variable is showing in the context, from the error. But can't be see by Twig. And the variable is being given to twig when I render the template.

 

I searched a lot of solution in the PrestaShop documentation who's mostly empty for this case of figure, and I been searching on google or with developers since 5 days now and I'm just stuck at the 'giving Twig my variable" step... Could someone see where the problem could occur ? Or if I'm doing something bad ?

Thanks you for having read that ! I really hope a solution could come from this topic

 

Edited October 27, 2022 by Alexandre B. (see edit history)