where to put static files in django code example

Example 1: my django template doesnt want to load the static file

STATIC_URL = '/static/'
STATIC_ROOT = os.path.join(BASE_DIR, "/static/")

STATICFILES_DIRS = ( 
    STATIC_ROOT,        
)

Example 2: django static files

{% load static %}
<img src="{% static "my_app/example.jpg" %}" alt="My image">

Example 3: static file link in django

STATIC_URL = '/static/'