To enable the IUS repository on your system, install the ius-release package. This package contains the IUS repository configuration and public package signing keys. Many IUS packages have dependencies from the EPEL repository, so install the epel-release package as well.
yum install \ https://repo.ius.io/ius-release-el6.rpm \ https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
yum install \ https://repo.ius.io/ius-release-el7.rpm \ https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
IUS packages are first made available in the ius-testing repository before being promoted to the main repository. When you install ius-release, the ius-testing repository is disabled by default. Enable it if you would like to participate in testing new IUS packages.
yum install yum-utils yum-config-manager --enable ius-testing