
Samsung Galaxy Tab S10 FE, 128GB, Blue
Every official firmware build for SM-X520N, newest first: one row per build with all regions (CSC) that received it.
Box codes of SM-X520N for different colors and markets. Firmware is chosen by the model code SM-X520N and your region (CSC), not by the SKU.

SM-X520

SM-X528U

SM-X510N

SM-X620N

SM-X626N
You can find the firmware on the model: SM-X520N page.
Yes, all firmware files for SM-X520N are 100% official, original, and obtained directly from Samsung servers.
To flash SM-X520N, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-X520N.