Add custom fields in admin category page Presta 1.7.6

[jef933]

Hi everyone !

As you can see , I've difficulties to add a custom field into category admin page.

More precisely, i found this hook : hookActionCategoryFormBuilderModifier 

but i can't register it , like it doesn't exist in prestashop.

However i find it on presta documentation.

Does anybody have already make this ? could you please help me ...

Thanks