Hi, I am using PsychoPy version 2025.1.1, under Win11. I have a small experiment I created with Builder (I know very little coding), that essentially presents images. I should integrate it with GazePoint GP3 eyetracker. I installed the plugin, set the GP3 as an eyetracker where I should. I also figured out that there is a way to start and stop recording in Builder (though I don’t know how reliable it is), however, I don’t know how to send markers to the eyetracker that indicate e.g. the start and end of fixation cross, the start and end of the main image i n each trial and the mouse response. It is clear that I need to include code snippets for this in the relevant routines (?) but I don’t know how those should look like. Proper timing is superimportant. The marker should be sent when the image actually appears on the screen not earlier or later. I read some threads but I could not find information on this. I know I should have a properly written code…but I just don’t have the ability to write a code from scratch (yet).