The TEMPLATE setting is a list of the template engines used when finding template files and rendering them.

The DIRS key within the TEMPLATE list denotes the directories where the engine should look for template source files.

DIRS must be absolute paths. Relative paths will not work.

So in practice, do this

import os

ROOT = os.path.abspath(os.path.dirname(__file__))
    
TEMPLATES = [
    {
        # …
        'DIRS': [os.path.join(ROOT, 'templates')],
    }
}

Instead of this

TEMPLATES = [
    {
        # …
        'DIRS': ['templates'],
    }
}