Already wired for I2C - no need to convert.
SDA: Connect to Gotek DISP_CLK J7 Pin
SCL: Connect to Gotek DISP_DIO J7 Pin
VCC: Connect to Gotek 3.3V J7 Pin
GND: Connect to Gotek VSS J7 Pin
Gotek J7 Pins:
https://www.ebay.co.uk/itm/128x32-OLED-I2C-White-Blue-0-91-Display-SSD1306-SD1315-IIC-Arduino-PI-IoT-UK/153983534553