R4 cards support boot9strap (ntrboot) CFW modification to your New 3DS(XL), NEW 2DS, 3DS(XL) & 2DS, after flashing, you can play downloaded 3DS cia. ntrboot is not recommended for tech newbie, wrong flashing may brick your console forever. Setup guide refer to https://3ds.hacks.guide/
Flash ntrboot to R4i-SDHC 3DS RTS in advance, backed-up flashrom available to revert to DS gaming flashcart. This service is provided for users who have no NDS NDSL or NDSi on hand but want R4i-SDHC 3DS RTS to complete 3DS system b9s cfw flashing.