On V6 you can edit the open key direct on the Settings menu.

If for some reason you can’t open this pleas follow the next.

For this tutorial we gonna need two pages:

1.- https://docs.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes

2 .- https://www.rapidtables.com/convert/number/hex-to-decimal.html

What we need to doe, is open first page that page contain a list of keys, as example i gonna search F8 on that page and as you see:

THE F8 KEYS IS DISPLAYED AS:

So the value wee gonna need to take is the Hexadecimal value on this case is the 0x77.

With this value we open the 2 page, and just insert that value on the Enter hex number FIELD, and click the green buttom.

One time we press the buttom, we should get the result on this case for 0x77 (F8) the final value is 119.

On this case what we need to remember is that decimal number "119".

Now to change the key, we need to open the FikitRDR2 folder, that should be on you AppData\Roaming\FikitRDR2, and open the file GlobalSettings.ini

Inside the file find the next line:

custom_key=0