Problem with button mapping settings

[glazier3031]

I have an HHKB and use macOS. I want to restore the original functions of Magic Keyboard on HHKB as much as possible, but I encountered some problems when using Karabiner App. I'm not a native English speaker, so maybe it's because I can't fully understand what the software menu means, please help me.

1. The system control functions of Magic Keyboard F1～12, such as increase/decrease brightness, increase/decrease volume, can be triggered on HHKB through fn+number keys after installing Karabiner, but
   It’s F6 that “turns on focus mode” on Magic Keyboard, but it’s still F6 in Karabiner. I searched for a long time but couldn’t find the function of mapping fn+6 to turn on focus mode in the GUI. If it can be solved by command line programming, please tell me how to do it, thank you very much for your help!

2. The Global key of the Magic Keyboard, also known as the "Earth" key, is very useful. I often use Global+Q to open the quick memo and Global+C to open the control center. It is very troublesome to lose this key on the HHKB. I want to map "press fn and G at the same time" as a Global key, just like pressing fn and Tab at the same time on HHKB is mapped to capslock, and pressing fn and A at the same time is mapped to volume down. I also did not find out how to achieve this requirement, because many keys including G are undefined blank keys after pressing fn, which is very precious on the HHKB where the keyboard space is scarce, and it is a waste not to use it.

Because I use translation software to translate this passage, there may be language errors or places that cannot accurately convey my meaning, please understand and include!
I don't know how to program, so if you need to write code configuration by yourself, please tell me how to write it, thank you for your patience and help!