Bodmer's bitbash sketch assumes a single bidirectional SDA pin.
4-line SPI defaults to individual SDI, SDO pins.
You can make ILI9481, ILI9488, ST7796 controllers use a single bidirectional pin in software.
I could possibly post you a more versatile bitbash sketch.
But since you appear to quote ILI9481 now, I have lost any confidence in anything you say.
Surely you bought the bare panel. It would have arrived in an antistatic bag with a printed label. It will have a part number printed on the ribbon or the back of the panel.
Bodmer supports ILI9481, ILI9488, ST7796.
David.