If you have another mac you can always use the disk utility to burn 10.4
How to Install Mac OS X 10.4 Tiger on a Mac from a Bootable USB Stick!
This is the MacOS Tiger challenge, where I see how it differs from Big Sur. It's great and especially cool because it features a Vintage Mac Collection mac, newer than the iMac G3 and G4 as well as the PowerMac and G4 Cube, but older than the iMac 27'. This is an iMac 5,2 with a Core 2 duo Processor. 512 Megabytes of ram. This can also be done on old Macbook, Macbook Pro, Mac Mini, Macbook Air & PowerMac G4, PowerMac G5