How to fix error while creating database schema via graphviz in django?

Question

Django

You need to create a database schema for your django project. I did everything according to the documentation: installed django_extensions, graphviz and pydot, everything is as it says here django-extensions.readthedocs.io/en/latest/graph_m...
The dot file creates without problems, but when I try to create a png file, the following error pops up:

Traceback (most recent call last):
  File "/home/user/Django/lib/python3.4/site-packages/pydot.py", line 1878, in create
    stderr=subprocess.PIPE, stdout=subprocess.PIPE)
  File "/usr/lib/python3.4/subprocess.py", line 848, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.4/subprocess.py", line 1446, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'dot'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/user/Django/lib/python3.4/site-packages/django/core/management/__init__.py", line 350, in execute_from_command_line
    utility.execute()
  File "/home/user/Django/lib/python3.4/site-packages/django/core/management/__init__.py", line 342, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/user/Django/lib/python3.4/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/user/Django/lib/python3.4/site-packages/django/core/management/base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "/home/user/Django/lib/python3.4/site-packages/django_extensions/management/utils.py", line 58, in inner
    ret = func(self, *args, **kwargs)
  File "/home/user/Django/lib/python3.4/site-packages/django_extensions/management/commands/graph_models.py", line 168, in handle
    self.render_output_pydot(dotdata, **options)
  File "/home/user/Django/lib/python3.4/site-packages/django_extensions/management/commands/graph_models.py", line 230, in render_output_pydot
    graph.write(output_file, format=format)
  File "/home/user/Django/lib/python3.4/site-packages/pydot.py", line 1774, in write
    s = self.create(prog, format)
  File "/home/user/Django/lib/python3.4/site-packages/pydot.py", line 1883, in create
    prog=prog))
Exception: "dot" not found in path.

As I understand it, the problem is that it cannot find the dot file, but I could not find a solution to the problem. Can anyone suggest how to fix this?