How i can add static files (css) to django web project

I have tested to embedded css style into html template, but it doesn't load css files, my configure as below, could you please help assist ?

checkstatic\showstatic\templates\index.html

<!DOCTYPE html>
<meta charset="UTF-8">
<html lang="en">
    <head>
        {% load static%}
        <link rel="stylesheet" type="text/css" href="{% static 'css/mystyle.css' %}">
    </head>
    <body>
        <img src="{% static 'logo1.png' height="200" width="200" class="d-inline-block align-top" %}" alt="">
        <h1 class="test">hahahaha</h1>

    </body>
</html>

checkstatic\static\css\mystyle.css

.test{
    color: red;
}

my settings:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'showstatic'
]
...
STATIC_URL = 'static/'
STATIC_ROOT = os.path.join(BASE_DIR, 'static')
STATICFILES_DIRS = [
   os.path.join(BASE_DIR, 'checkstatic/static/')
]

when i access the index site, it only apply h1 tag, it can not load red color as the css config.

Solution

Statics are used to get and use complete files (css, images, js, etc), in your image it should be:

<img src="{% static 'logo1.png' %}" height="200" width="200" class="d-inline-block align-top" alt="">

Leaving the properties of the img outside the static block.