Download the archive for your system from the release page here, and extract it.
# example for linux amd64
wget https://github.com/thomiceli/opengist/releases/download/v1.10.0/opengist1.10.0-linux-amd64.tar.gz
tar xzvf opengist1.10.0-linux-amd64.tar.gz
cd opengist
chmod +x opengist
./opengist # with or without `--config config.yml`