Samsung is not a fond of installing third party firmwares on the S9 FE but you can do that by installing a custom recovery like TWRP to make that happen.
Galaxy Tab S9 FE and FE+ 5G, WiFi TWRP download
Category: Galaxy Tab S9
Root Galaxy Tab S9 X710 and custom kernel
If you own a Samsung Galaxy Tab S9 X710, you can now root it by installing this custom kernel. You would need to on the stock ROM. Only UH (KDP, RKP) protections are disabled. Everything else, including Knox, remains intact.
Download Galaxy Tab S9, S9+, S9 Ultra, S9 FE TWRP custom recovery
Samsung Galaxy Tab S9 is great tablet but you can extend its functionality by installing TWRP, an example of custom recovery. The custom recovery is available for all versions of S9, including S9+, S9 Ultra, and S9 FE.
