Upgrading to sketch version 4 for RPICT v3
RPICT unit version 3 do not have auto-reset feature and as a consequence it is not possible to upload the sketch directly from the Raspberry pi.
Nevertheless installing version 4 of the firmware is still possible.
One should acquire an Arduino UNO first. These are very cheap on most marketplace. Even clone ones can be used.
The first step is to remove the microcontroller on the RPICT board. For this use a flat screw driver and gently lift it up from its base.