How to display on the category page a list of subcategories and posts corresponding to these categories?

Question

Twig

Guys, I ask for help.
On the site, I created the main category and subcategories:


I need the subcategories and posts corresponding to these categories to be displayed on the page (as in the first screenshot).

I'm trying to make it look like this:

{% for post in blogPosts.posts %}
{% for category in post.categories %}
    {{ category.name }}
{% endfor %}
    <h2>{{ post.title }}</h2>
{% endfor %}

and it turns out not quite what you need, all posts from all categories are displayed, and the name of the category is assigned to them, i.e. the name of the category constantly appears above the post from that category.


And I need to display only posts of a certain category, and in the sequence:
Category
name1 -post from category 1
-post from category 1
Category
name2 -post from category 2
-post from category 2

How can I make such a filter in Twig? ask for help from experienced fighters