How to dump tv firmware? - I want to update my tv firmaware but before update i want to "dump&q

I want to update the firmware of my TV but before updating I would like to "download" the original firmware directly from the TV.
I looked for instructions on "dumping" the firmware but I could not find instructions or guides that illustrate step by step the operations to be performed.

I therefore ask if there is any guide or manual or video available that illustrates how to dump the original firmware from a TV based on the MST608DMBT motherboard or on a similar card

These are the characteristics of the TV that I could read in maintenance mode (by accessing with SOURCE 2580)

Mainboard: MST608DMBT
SOFTWARE VERSION: V1.0.0.0
MAIN BOARD: TP.MS3663S.PB818
CHECKSUM: 0X5B86
BUILD TIME: 2019-01-26 11:16:24

FIRMWARE: MSD3663_S_OB3353_43.BIN

Post a picture of the back cover of the TV

The image of back.....

But the question is: how can I dump firmware? I want to learn how to.....

Thank you and best regards.