TCL provides a Mobile Upgrade Tool for PCs to help users update their devices manually if wireless updates fail.
Make sure the firmware matches your specific model (e.g., standard vs. the Verizon TCL 20 5G UW specific version of the firmware (like Android 11 or 12) or trying to fix a specific issue like a boot loop? How to Download Firmware for TCL 20 5G UW?, How To firmware tcl 20 5g link
How to Download and Update TCL 20 5G Go to product viewer dialog for this item. Firmware Keeping your TCL provides a Mobile Upgrade Tool for PCs