Variables between Twig files and MD?

I've got this chunk of code at the Twig file

{% for feature in page.header.features %} 
 {% if feature.teste %}
            <h1>{{feature.teste}}</h1>
{% endif %}
{% endfor %}

Then at .MD file I've got this

features:
- teste: aeasd

Isn't suposed to output <h1> aeasd </h1>?

I guess I need to register this as a variable or smth like that but I've seen anywhere to do that.

Ty for you attetion

Your code works when I try it. Are you sure the right twig file is being used?