This is last line of error.log

[Tue Aug 17 10:58:43.663287 2021] [wsgi:error] [pid 9685:tid 140291094402816] [remote 127.0.0.1:40518] PermissionError: [Errno 13] Permission denied: '/home/not/.local/share/virtualenvs/textapi_flask-mXLf-cmV/bin/activate_this.py'

Edit 1: used sudo chown -R www-data:www-data /var/www/html/textapi_flask and sudo chown -R www-data:www-data /home/not/.local/share/virtualenvs/textapi_flask-mXLf-cmV/bin

to change owner but still getting same error