[Q] Change & customize menu items and functions for Six axes robot (not a 3D printer )

[jafarniknam]

Hi
I used MKS Robin v2.4 (+ its special TFT )for my six axis robot with marlin 2.0 FW (using feature : linear axes = 6 ) and change 320*240 UI of marlin . ( this file : Marlin\src\lcd\tft\ui_320x240.cpp ) But now I can't purchase mks robin mainboard in IRAN and It's hard to buy . so I decided to use MKS GEN V1.4 + MKS TFT32_L V4.0 .
Now I should use open source BIGTREETECH Touch Screen Firmware . I want change some menu functions and delete additional menu items like nozzle , Extruders and etc ( because my robot is not 3D printer ) also add some motion control (move and home ) of axis U , V , W ( additional axes ) .

can anyone help me how can I do this ? which source files and headers should I check ?
Sorry for my English !!
Thanks .