The MP20 is a two channel pre-amp, there is no interface to the computer.
If the MP20 is feeding the input of another device that is connected to the computer, then that is the device you'd be looking for updates.
If the interface was made by PreSonus you can visit our product download pages to obtain the latest release update.
If the interface was not made by PreSonus, contact that manufacturer for an update.
If you're not sure, log a support request with us so we can further assist you at https://support.presonus.com