Where do I put 3do bios?

Sorry, but I am new at using this. I know that you are supposed to put them in the frontend system directory. Could someone give me a step by step guide on how to do it? Thanks.

Go to settings > directory and you’ll see an entry for ‘system’ that should say ‘default’. Change that to some directory (could be in your RetroArch directory, could be somewhere else; just make sure it’s user-writeable [i.e., not in Program Files, etc.]). Put your BIOS images in that directory that you chose.

Is there anyway to get that core to display the BIOS boot screen? Or did that only come up with No Disc in the drive… can’t get a clear confirmation either way - and never seen any 3DO models in real life to test lol.