Where can I download the Yosemite.app file? (NOT .PKG or .DMG!!)

I have a 2018 macbook pro, and an old 2009 iMac that needs to have yosemite reinstalled. Problem is that the 2009 OS is no longer booting (data was nuked). And I tried getting the .app for yosemite from the dmg on my 2018 but it's incompatible!!! Damn you APPLE! I have no other way to make a yosemite installer other than getting the Yosemite. app and putting it into macdaddy's Install Disk Creator. The basic apple install usb instructions are bullshit, they don't work for my situation and it's honestly regarded that apple doesn't just have their .apps for download. WTH