Directory index forbidden by Options directive: /var/www/

I am trying to fix this issues I get a forbidden error when i try and type in my ip address

error message

Forbidden

You don’t have permission to access / on this server.

I then checked the apache logs tail -f /var/log/apache2/error.log

The error returned was:

Directory index forbidden by Options directive: /var/www/

I have tried various approaches

chown -R www-data: /var/www/mydirectory/public_html

from what i understand from a simple explanation apache uses www-data as a user.