very old safari version

hi
Trying to install opencorelegacypatcher on an old iMac. The iMac is from 2016 and the latest version on it it OS X 10.9.5. The difficulty is that the safari version is also an old one and it doesn't really load different the OpenCore side so I can download it on a Disk. I tried download different Browers but of course non work because the iMac's Software is to old. I read on The Open Core side that I should not / can not use an other devise to download it onto the disk it has to be done with the dives you want to update. Does any body has any ideas or tipps how I can still upgrade the iMac. Would be much appreciated and thank you in advance for your help!