Change the path to your private key in ansible.cfg:
private_key_file = ~/.ssh/express42
Change IP address of freeradius host in hosts file.
Look into defaults and change asa_internal_iface_ip to the Cisco ASA's inside interface.
Also, please note the value of shared_secret variable, as it will be used later in the Cisco ASA config.
You can use the following command:
ansible-playbook playbooks/freeradius.yml