Recommend to use Ubuntu 18.04 because Docker currently not have the package for 20.04 (wrote at 2020/05/09)
wget https://launchpad.net/~rafaeldtinoco/+archive/ubuntu/lp1871129/+files/libc6_2.31-0ubuntu8+lp1871129~1_amd64.deb sudo dpkg --install libc6_2.31-0ubuntu8+lp1871129~1_amd64.deb