Help with Raspberry Pi 3B+ Video Games Machine

I really need some help with the recalbox console I purchased (picture attached).
My ultimate aim, is to be able to boot from an external portable drive (2TB) because a USB just will not have enough space. FYI it is running Dragonblaze 6.0, the internal SD card is formatted in Lynux, and I have a Windows 10 PC.
I managed for format my external drive to FAT32, went into the settings which found my drive, and have sucessfully got the console to boot from the external drive. After the initial intro, it boots to a screen that is expecting me to map buttons for an external controller. I tried something different, converted the internal SD card from Linyx to Windows, coped all those files over to the directories already created by the machine on the external drive, thinking there might be some bios files that it might need to boot correctly. It did not change anything. What have I done that prevents the console from booting properly? Is it the difference between the original SD card being formatted in Linux and the external drive being in Windows? Lots of people have said “upgrade your os” but firstly I don’t know how to do this on a Linux based SD card with Windows, and secondly, I believe there is a much simpler solution to my problem. I have seen big upright console machines with the exact same console as mine that they claim can run pretty much every game, so It can be done, I just do not have the expertise to know how, and I have either been shunned or totally ignored when someone tells me to visit a youtube video, and its of a person making their own games machine from a little Raspberry Pi and an external controler. I don’t believe what I am wanting to do is impossible, because if it was, firstly there would be no option to choose which drive you want the system to get your data from, and secondly, my console would not be happily booting from that external drive. I need some help from someone with a bit of knowledge, and someone who has the patience to walk me through what I need to do, or point out what I’ve done wrong, and someone who has the time to help me get to where I want to go. I thank you all in advance. Richard