https://dsiguide.me/
http://dsi.cfw.guide/
Been through both of these sites and can't find a answer. First thing I did before posting here.
You need a exploitable Dsi game, but if you don't have one of these you have to inject a exploitable DSi game.
https://gbatemp.net/threads/dsi-downgrading-the-complete-guide.393682/
Also you need Unlaunch for Hiya CFW
Okay, sorryI'm lost to what you're saying. I've got unlaunch and HiyaCFW installed. I just want to be able to boot my R4 flashcard in dsi's patched menu.
Is it the non SDHC R4? If it doesn't show up in system menu when you insert it, you will have to use NTR Launcher to boot it:
https://github.com/ApacheThunder/NTR_Launcher/releases/tag/2.1
This should get your R4 working.