you need to get the dtbo file, take a look a the page https://github.com/recalbox/recalbox-os/wiki/Utility---Use-of-fbcp-for-small-TFT-screen-%28EN%29 and https://github.com/recalbox/recalbox-os/wiki/TFT-Screen-SPI-Bus-(EN) if you do not use the 4.1 release