html file have something wrong Registration Form not submitting in Django

My html file have some issues but I can’t figure it out what the problem actually is.
Can anyone Identify what really the problem is.

Django form returning Validation errors for fields that have never existed

What is the valid reason behind why it’s:

Django multi-selection in the form with CBV django

I have 2 models: Group and Post.
Group is ManyToManyField to Post