get https://api.finx-s.qwist.cloud/category-tree
Retrieve the complete category tree as a single-linked list. The category name is rendered depending on the language given in the Accept-Language header. Each list entry has an id and a parent_id linking a category to its parent category (e.g. the category "Online-Shopping" is linked to the parent category "Living"). Categories on the 1st level have a parent_id value set to null.