3 level of opencart subcategories?

Question

PHP

Hello, tell me how to implement the output of the 3rd level of the subcategory Like
this:
-fruits (1st level)
-- topical (2nd level)
--- pineapple (3rd level)
--- coconut (3rd level)
--non-tropical (2nd level)
- -- apple (level 3)
--- pear (level 3)
I want to display category data on the category page directly without modules, subcategories of level 2 brought out, but I don’t know how to 3
Thank you in advance