Prohibition screen during legacy patcher Sonoma/Sequoia install boot

Help. I don’t know what I’m doing wrong. I have a 27 inch 2017 iMac running Ventura I’m trying to upgrade to Sonoma or sequoia via open core and a flash drive. I follow all the instructions to this linked video perfectly and with the most updated OCLP, I get all the way to the recovery menu and clean my drive and click to install Sonoma, and it starts installing but on the first reboot it boots to a black screen of a circle with a slash through it and a support.apple.com/mac/startup link. I just don’t know what to do.