This is the standard method for most users.
Updating firmware is not like updating a smartphone app. A failed installation can permanently "brick" your TV (turn it into an expensive paperweight). firmware tcl 50ep660 upd
Moreover, owners should be wary of third-party firmware sites. Unofficial builds for the 50EP660 (often claiming to unlock advanced features or remove ads) have been known to break HDMI-CEC control or disable the TV’s local dimming logic. This is the standard method for most users