The 64bits image can be found here: https://ubuntu.com/download/raspberry-pi
You can use 20.04 LTS version or 22.04 LTS version one. Preferred the 22.04 LTS one because it manages USB boot at last!
To manage ip setting and an ubuntu account not expired (as well as a non update kernel at boot first, this will be managed by the ansible install), we use cloud-init files.
Template files can be found in the cloud-init folder and it must copied in the /boot partition just after the image burn. Just Change your targeted IP address in the network-config file.