Websites like HardReset.info maintain a collection of official stock firmware files for various TCL models, including the TCL 20 5G.
This is the standard wireless update method. To check for updates, go to Settings > System > System Update .
Manual flashing should only be performed if FOTA or the Mobile Upgrade tool fails, as it carries a risk of "bricking" the device.
Ensure your battery is at least 30% or higher to prevent a shutdown during the process. Identify Tools: For MediaTek (MTK) variants, use the SP Flash Tool .