Conda : solving environment failed when downloading kinetics 700 dataset

I tried downloading the kinetic dataset following this github repository github_link I followed the instructions first

git clone https://github.com/activitynet/ActivityNet.git
cd ActivityNet/Crawler/Kinetics

after that I tried creating the environment

conda env create -f environment.yml
source activate kinetics
pip install --upgrade youtube-dl
but i changed and used :```

conda create -n env -f environment.yml

But I got this message Solving environment : failed PackageNotFound Error : the following packages are not available from current channels to search for alternate channels that may provide conda package your looking for navigate to http:// anaconda.org

how can I fix this and download the dataset ?