Finding specific firmware files like can be tricky because they are often model-specific and hosted on technician forums or manufacturer support pages rather than general websites.
It looks like you’re searching for a specific for a television, likely a 43-inch LED TV using an Mstar chipset.
If you already have the .rar file, you usually need to extract the MstarUpgrade.bin file to the root of a FAT32-formatted USB drive to start the update.