In Puppet6.7 you have to enable Puppet Platform Repository instead.
Enabling the Puppet platform repository makes the components needed for installation available on your system.
The process for enabling the repository varies based on your package management system.
Enable the Puppet platform on Yum:
Before you begin Identify the URL of the package you want to enable based on your operating system and version.
Logged in as root, run the RPM tool in upgrade mode:
sudo rpm -U <PACKAGE_URL>
Note: For Enterprise Linux 5, you must download the package before running RPM:
wget https://yum.puppet.com/puppet6-release-el-5.noarch.rpm sudo rpm -Uvh puppet6-release-el-5.noarch.rpm
For example, to enable the Enterprise Linux 7 repository:
sudo rpm -Uvh https://yum.puppet.com/puppet6-release-el-7.noarch.rpm