Bootstrap Navbar Logo not found

"static" folders are needed in Django like in flask. https://docs.djangoproject.com/en/4.0/howto/static-files/

put your image in the static folder and call: static/logo.png instead of logo.png.

file structure:

HTML File Code Example:

{% load static %}

{% block content %}
 <!--Navbar-->
 <!-- Just an image -->
 <!-- Image and text -->
 <nav class="navbar navbar-dark bg-dark">
 <a class="navbar-brand" href="#"">
   <img src="{% static 'posts/images/logo.png' %}" width="30" height="30" class="d-inline-block align-top" alt=""/>
EtherWAN Product Map
</a>
</nav>
<!--End Navbar-->    
{% endblock content %}

the file structure can be mainapp/ -> static/ -> images/ logo.png