how to add static files in django

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

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

STATICFILES_DIRS = ( 
    STATIC_ROOT,        
)

STATICFILES_DIRS = [
    BASE_DIR / "static",
    '/var/www/static/',
]