The most reliable source is the official support page of your laptop brand. Look for the "Optical Storage" or "CD/DVD Drive" section under downloads for your specific laptop model.
Official updates are distributed by the PC manufacturer that installed the drive (e.g., Sony, Toshiba, ASUS, HP). matshita bdmlt uj240as firmware update
Once rebooted, verify the firmware version again using Device Manager. If it has changed to the newer revision, the update succeeded. The most reliable source is the official support