The following guide is for educational purposes only. Installing a custom ROM requires unlocking the bootloader, which will wipe your device data and may void your warranty. Additionally, the Sony Xperia XA1 uses a Forever Locked (ABL) security mechanism on certain firmware versions. If your device is on a locked firmware, you cannot install a custom ROM. Proceed at your own risk. I am not responsible for bricked devices or voided warranties.
If your device passed the check above, follow these steps on Sony’s official developer world website or use the guide below. sony xperia xa1 custom rom
KEY with the code Sony emailed you.