You need a firmware that supports the OLED (Prusa firmware does not).
Firmware for Caribou and Prusa can be found here: https://caribou3d.com/en/content/10-caribou-firmware
Source code can be found on github: https://github.com/Caribou3d/Caribou-Firmware
The OLED display is a bit thinner as the regular LCD and needs an updated cover, holders, and knob. STLs can be found here: https://github.com/Caribou3d/Caribou-MK3/tree/master/STL/full-kits/10mm-xyz/Frame/OLED
Included: two flat ribbon cables (70cm)