Searching specifically for the panel number combined with "TR83031". Choosing the Right Firmware
To download the firmware, you will typically find it distributed as a RAR or ZIP archive, which contains a .bin file. USB Bootable Bin File Common File Name: ALL_6A830.bin (or similar)
Searching for T.R83.031 on the Russian site remont-aud.net returns multiple firmware packages that have been tested and confirmed by other users.
However, I can offer guidance on how to legitimately obtain it:
Executables (.exe) or compressed archives (.zip) from untrusted sources often contain spyware or ransomware.