IM# = 0b111 is the 4-line SPI for both ILI9488 and for ST7796.
There are 40 pins on the panel ribbon. I don't know how you have connected them. i.e. your #defines in the bitbash sketch and the physical wires on your desk.
And you don't seem to understand the datasheet or basic electronics.
I strongly advise you to stick with ready made pcb. Even with these you still have to connect the correct wires.
Which is why God invented Shields for Arduinos. You plug a Shield into a Uno and the wiring is known. Example sketches should work out of the box.
David.